In the "Jimmy Savile" sketch in the "Religion" episode, Pope Benedict XVI's letter was meant to end with the words "Sieg Heil!" but the BBC would not allow it for legal reasons (they thought it sounded like the Pope was endorsing the Nazis). Instead they used the only German that Jerry Sadowitz knew, which was "Ich bin ein grosse koten mit zwiebein", which translates as "I am a potato salad". It was also Sadowitz's idea to deliberately wear a wig that was too small to cover his real hair.
Source: DVD Audio Commentary
The broadcast of Series 3 was reportedly brought forward to March from a planned mid-Spring start, to avoid clashing with the early May elections to the European Parliament, in light of a number of political jokes in Lee's routines, particularly at the expense of UKIP.