Yeah, give it a shot, it's been known to help. If that doesn't do it for some reason, if you haven't already make sure you've done the General Setup stuff in
this thread, things like Spotlight drive indexing can also cause PT to throw up a lot of errors.
The other potential problems I see are that you're sorta barely keeping afloat with only 1.5gb RAM (7.4 needs more than 7.3 due to elastic audio), and you could also try moving your FW800 drive to a 400 port, that also has been known to fix a glitch or two, although usually more with laptops and older G4's.