"There is Not Enough Memory or Disk Space to Complete the Operation"

Hi, Ive posted this problem before but had no luck with a solution. I cant use the clipboard in Microsoft Word, e.g. whenever I try to paste something I get the message seen in the title. I also cant copy and paste in Safari or TextEdit, although I can copy and paste in Stickies. I have 10 GB free on my 40 GB hard drive after deleting many movies, and I have 640 MB Ram on an 867 Mhz G4 Powerbook running Jaguar. Ive repaired permissions, zapped my PRam, deleted caches, tried to fix things using Cocktail, restarted numerous times, and nothing works. This is the only problem Im having, outside of Apple System Profiler quitting after being open for a few seconds.

Thanks a lot, Dan

Reinstall Office?
Install the latest office patch?
Reinstall & archive system?