Has anyone else had a problem with their 990 not holding the preset radio stations? Maybe I'm just not setting them correctly or sometime if I know I won't be downstairs for a while I will cut off the main power on the back of the 990 and it could be a week or more before I make it back downstairs, could this have something to do with it?

I've not had that problem, but I haven't used the main power to shut the unit down - that's certainly a candidate for the behavior. I take it that no other settings are lost?

Nope, all other settings stay the same.

Odd - I'd probably leave the main power on for a week or so without bringing it out of standby and see if it still remembers...