MS Office, iTunes, iPhoto usage / setup

Every time I launch MS Office, iTunes, or iPhoto, the apps behave as though this is the first time I've ever run them. The Office apps know they've been registered, but keep asking me for setup information (like the user name and initials) -- which I provide but is not being stored. I'm sure there is a preferences file somewhere that either isn't being updated or isn't created, but I don't know which one, or where, or how to force it to exist. When I supply the information, the apps run fine; it's just very annoying (and time consuming) to have to go through that process every time I open Word, iTunes, Excel, etc.

As far as I can recall, this began happening when I installed Office 2011, but also wanted to keep running Entourage from Office 2008.

I did go through Keychain Access First Aid (though I'm not having problems with passwords -- that I know of), and got this error:

Repair started

Checking keychain configuration for gwenpeterson (user ID=502)

Home directory is /Users/gwenpeterson

Checked login keychain

User differs on ~/Library/Preferences/com.apple.security.plist, should be 502, owner is 0

Owner not corrected on ~/Library/Preferences/com.apple.security.plist, reason: The operation couldn’t be completed. Permission denied

Checked default keychain

User differs on ~/Library/Preferences/com.apple.security.plist, should be 502, owner is 0

Owner not corrected on ~/Library/Preferences/com.apple.security.plist, reason: The operation couldn’t be completed. Permission denied

Checked contents of ~/Library/Keychains/login.keychain

Checked contents of ~/Library/Keychains/Microsoft_Intermediate_Certificates

Warning: some problems were not fixed

Repair failed

Don't know whether this is related or not ... but I also couldn't find the /Library/Preferences folder at all to try to fix this.

Finally -- and again, I don't know whether this is related -- I can't seem to prevent applications from launching on startup that I set up a long time ago. I remove them from the list in the System Preferences dialog, restart the system, and they're back on the list. Clearly, something (or THINGS) are not getting updated properly ...

Help!