MS Word not able to save open documents/quitting unexpectedly

Question

I've had the following problem more than a few times since I've had my iBook (just over a year): Sometimes when I have a Word document open that I'm working on I'll get one of two messages when I try to save the document. One says something to the effect that Word is unable to save the document because the "disk is full," or a message appears that says that Word can't save the document because too many "applications" or "documents" are open (I can't remember which one is specified). Then another box pops up that says something about "autorecovery" being postponed or unable to work. Finally - the icing on the cake - Word shuts down and a message about Word "quitting unexpectedly" comes up.
When this sequence occurs, anything that I've written since the last time I saved the document is gone. Lovely. Who cares that I just wrote the clearest articulation of my thoughts for the day, right? (I'm currently working on my dissertation, so this is VERY FRUSTRATING, to say the least.)
I have tons of space left on the hard drive, so I know that no "disk is full." Also, I find it hard to believe that having, say, two Word documents open along with DSS (an audio program for transcribing) is too much for the computer to handle at once. (I mean, if it were a PC, sure, I might be able to believe that this sort of thing could overload it and cause a hitch, but pleeease, with a Mac? Isn't that the whole reason I was sold on these fancy new-fangled machines?) Plus, this problem has also occurred when I have only one document open.
Just to add a little more info. to the puzzle, I already reinstalled MS Office again, thinking that perhaps it just wasn't properly installed the first time. No change. I've also asked a tech through Apple Care about it, and he guided me through checking my hard drive for any damage, etc. We found nothing out of the ordinary. Finally, a friend who has the exact same copy of MS Office on his desktop Mac has never had any problem with Word.
Any advice would be much appreciated.
iBook G4   Mac OS X (10.4.5)  

Answer 1

as first step try creating new user in Accounts system preference, log in as new user and try running Office.
if it works that way, issue is with some preferences or cache files in the original user account.
if it does not work under new user, issue is system-wide with Office specific files or the OS.