I had a problem where I couldn't change channels which turned out to be because I hadn't selected 'visible' (thanks to Greg Frost for his post on tier 1 dvico) and now I can change channels until I hit either end of the available channels - ie if I try to select a channel previous to the first channel , the backend dies. I am assuming it should change to the last channel. The same happens if I try to go past the last channel assuming it would give me the first channel.
I suspect this is a problem with the channel database?? but this is guess and it is all way above my head now.
I am using 5a22 and I haven't tried updating any packages with synaptic yet.
Any appropriate suggestions appreciated.

TIA

Disregard. I had a mix of valid channels and channels with no channel number in the Channel Editor window. Both of these channel lots where marked as visible but when I made the channels with no channel number 'not visible' problem went away. The channels with no channel number came from mythfilldatabease somehow, now I just have to get the program guide to work.