[X4U] iTunes problem

[eleventhvolume]

I use iTunes a lot to play music so the fact that I'm finding it quitting on
me without warning repeatedly is mighty frustrating. I'm just playing a
series of albums from a standard playlist, but it's quitting at the end of
each song. I've tried logging out and in again, rebooting and this is 7.0.1
- can anyone recommend me what I can do? I'd try deleting the preferences
file, but don't know where to find it. I tried downgrading to version 6 via
my backup, but it tells me it can't run because of the new library file.

Thanks for any help you can give.

All the best, Colin.