The biggest mystery to be solved in this police procedural is how it got recommissioned after a widely panned debut two years ago. The format borrows heavily from Moonlighting, purporting to be a comedy drama about a dishevelled detective (Toby Stephens) tackling crimes and sparking off a sassy female sidekick - Spooks' Miranda Raison has stepped in after Lucy Punch jumped ship. Upon examination of the evidence, there's little comedy and hardly any drama to recommend in tonight's opener about a car dealer's murder.

Miranda Raison: I'm completely different to Lucy Punch

Vexed newcomer Miranda Raison has insisted that she will be a "completely different" influence on the show to her predecessor Lucy Punch.

Quite a few people weren't sure what to make of the BBC's detective-mystery-comedy-thing Vexed during its brief period on air in 2010, but we've been assured by the cast that this second series is a lot stronger - and who are we to doubt them?

Toby Stephens is back as the cocky, incompetent DI Jack Armstrong and this time he's joined by Spooks actress Miranda Raison as DI Georgina Dixon, who is replacing original lead actress Lucy Punch. Only time will tell if the new duo are dynamic or dull - but if Raison can boast banter like that in the clip from series one, then perhaps this could be Vexed's moment to shine.

A quick chat with Vexed star Miranda Raison

After making her name as the ill-fated spy Jo Portman in Spooks, Miranda Raison is chasing bad guys again this week in a new series of the offbeat BBC2 crime comedy drama Vexed.

Vexed is back in production

How about a bit of good news for the middle of the week? Yes? OK then - detective comedy Vexed has begun shooting the next series with stars Toby Stephens (Jane Eyre, Robin Hood, Cambridge Spies) playing D.I. Jack Armstrong, and Miranda Raison (Spooks, Merlin, Married Single Other) playing new character D.I. Georgina Dixon.

Not unlike the desolate northern seaside resort in which it is set, this new series's brand of whimsical no-hoper comedy has definitely seen better days. That said, its tale of a band of plucky nutters, has-beens and never-will-bes uniting to save their local sweet factory from the clutches of an evil property developer is not entirely without charm - mostly thanks to the appealing cast led by Sue Johnston, Tom Ellis, Miranda Raison and Shaun Dooley. All the more bizarre then that the BBC One's schedulers should want to strangle it at birth by placing it in a ludicrously late slot, especially when the best they had to offer earlier in the evening was yet another yawn-inducing Inspector George Gently repeat.

"You're such a girl," Lillie (Lucy Davis) teased her partner Eddie last week. Unwittingly, perhaps, she gave away the secret topsy-turvy formula underpinning this series. All the men are acting like sappy romantic fools, while the women are bored witless by talk of bridal magazines and marriage.

Davis, in particular, whose character faces a tribunal tonight for thumping a violent husband (not hers), continues to turn in a very odd performance. Every line is delivered flippantly through clenched teeth, suggesting she's either had her jaws wired shut, or she's a superior being from another planet and is merely humouring these pathetic humans she's been forced to live with.

But there's one startling change this week, as Abbey's (Miranda Raison) eyes have switched from brown back to blue. Perhaps this is down to the physical effort of resisting Clint (Ralf Little). It's been a month and he's about to be put out of his misery.

Romantic comedy drama has always been a precarious juggling trick to pull off, especially in the shadow of the Cold Feet's unassailable reputation. So all credit to writer Peter Souter for even attempting the feat with Married, Single, Other.

An ensemble piece, the show uses three contrasting pairs to explore various aspects of heterosexual, thirty-something, white, Anglo-Saxon coupledom. There is one black character, but so far she has had to conduct her relationship off-camera.

First up are Lillie (Lucy Davis) and Eddie (Shaun Dooley), partners and parents for 16 years, but yet to commit to marriage. Then we meet Babs (Amanda Abbington) and Dickie (Dean Lennox Kelly), practitioners of wildly satisfying sex, but emotionally incompatible and financially insoluble. Finally there's bed-hopping playboy Clint (Ralph Little) cherishing an uncharacteristic devotion to Abbey (Miranda Raison), a beautiful model who is tired of the attentions of shallow men.

So far, so formulaic, but Married, Single, Other really does strain to impress with dialogue that is clever to the point of infuriating. All of the characters, including the teenage cast members, effortlessly exchange the kind of badinage that looks great on paper, but tests an actor's abilities, and patience, to the limit. Davis and Dooley just about pull it off, everybody else struggles to convince.

Little has the hardest time. His casting as a smooth-talking, worldly-wise ad man/lothario is irretrievably undermined by the first shot he features in, with bare chested Clint seen sitting in his bed beneath a giant soft-porn nude photo that would offend the sexual sophistication of a 12-year-old boy. Quite how everybody involved failed to realise that this visual shorthand screamed 'I am emotionally and sexually retarded' is beyond me.

Clint, the show labours to assure us, is flawed, but likeable and this is largely how I feel about Married, Single, Other. There's not enough comedy and too much schmaltz, but episode one did contain several surprises and one genuine shock, with the characters sufficiently engaging to merit sticking with a little longer. Which isn't the advice I'd give to Abbey regarding Clint.

Married, Single, Other is more obsessed with matrimony than even Iain Duncan Smith. ITV's new six-part comedy drama asks us to consider which is the most natural state for a grown-up - marriage, being single or living together. It is already hurtling towards the conclusion "none of the above". We refer first to Lillie and Eddie, not only because the actors Lucy Davis and Shaun Dooley make them the far most compelling characters, but because they appear to be content, and have been, so we are told several times, for 16 happily unmarried years.

The only tension in the relationship is Eddie's determination to marry Lillie, a desire that manifests itself in ludicrous romantic gestures on her birthdays, on one of which we join them. "May I refer you to the window?" asks Eddie, opening the curtain on a collage of post-it notes that spell "Will You Marry Me?" Eddie, a blameless paramedic and all round good sort, is a sentimentalist, so soppy you hardly realise that towards the end of the episode he has entered the euthanasia debate on the side of do-not-revive.

He is further goaded toward the altar by the neuroses of his 11-year-old son, who in an embellishment the writer Peter Souter should have thought better of, is a child prodigy and speaks in sitcom clever-clever. Joe (Jack Scanlon) is so anxious that his parents do the proper thing he scripts his father's proposal speeches in a scrapbook. Lillie is having none of it, not merely because she is happily in love as she is (which would have done for me) but because she works at a refuge for battered wives. By the end of last night's opener, rather than book Joe into therapy with her mate Babs, she has relented, however. In the Richard Curtis moment we all feared, she proposes to Eddie at her birthday party.

Among the guests are, of course, Babs who is married to a loser called Dickie, although you might want to abbreviate the name. Dickie, an all-night online gambler, get-rich-quick fantasist and biker, is so broadly written that Dean Lennox Kelly does well to make any sense of him at all in his performance. If only Amanda Abbington could have made us see what he sees in the dreary child shrink she plays. Meanwhile, the inveterate Lothario Clint, played by Ralf Little, has fallen for a blonde model called Abbey, played by Miranda Raison who, natch, is not a bimbo after all but well on to him. Clint: "You have only just met me" Abbey: "I have met you a thousand times before."

Where Souter and his executive producer Andy Harries are going dramatically rather than thematically with all this, I am not sure, and maybe that is a good thing. Souter has mentioned Richard Curtis's name and Andy Harries made Cold Feet, still the gold standard for this kind of post-watershed soap. The programme's titles carry the words "married", "single", "other" with boxes next to them and there is more than an element of box ticking in both the piece's premise and execution. The dialogue needs to unclench and the story needs to be given time to grow organically as the characters, one prays, deepen.

It's high time we had a decent comedy-drama to get our teeth into, and this new Monday night six-parter looks like being just the job. With a fine cast of instantly recognisable faces, including Ralf Little, Lucy Davis and ex-Spooks star Miranda Raison, it centres on three decidedly different couples, each with their own distinctive hang-ups. Babs (Amanda Abbington) looks set to dump her loveable but hopeless husband Dickie (Dean Lennox Kelly), while Clint (Little) seems incapable of more than a one-night stand - until gorgeous model Abbey (Raison) walks into his life.

As for Eddie (Shaun Dooley), he still can't persuade partner Lillie (Lucy Davis) to marry him, even after 16 years - but can the couple's youngest son seal the deal for him?