I was wondering if anyone knew if/when/are any seasons after season two available in the states?

I got the first two seasons a couple years ago, but I have yet to find seasons after that. I can only imagine that the US release did not break sales records, but I thought the show got better as it went on (until private goody became George).

I'm not sure why, but only those two series were released in the US. We've only had series 3 here. Quite, quite bizarre.