Repair permissions only works on Apple-set permissions of system files. If a rogue app that you installed is what is causing your Mac to go all squirrely, repairing permissions won't do anything.

How to Change File Permission From Read-Only to Read-Write on a Mac. The Mac OS X Sharing & Permissions settings allow you to change who can view or edit certain files. Changing a file from read ...

"Mac OS X 10.4.3 does not fix the problem, neither does Office 11.2.1, even though my research shows that both Apple and Microsoft are aware of the problem.

Conclusion The “Word Cannot Complete the Save Due to a File Permission Error” issue on Windows can be resolved by checking the file location and permissions, renaming the file, or ...

This can be the result of a permissions problem, or a potential flaw in the way that Mac OS X's networking components traverse across filesystems to save files.