My N73 is absolutely fine. I have actually upgraded it by using Nokia’s software updater so it is now running the same firmware as the N73 music edition. I’d give that a go if you’re having issues although it sounds more like a hardware fault on your phone – perhaps a new battery is needed or something – no idea!?
jon – does your n73 keep powering down as mine is doing my nut in, lcukily mne flatmate works at 3 !!