Microsoft Office 2011 "Recent Items"

On my new iMac 27" (late 2013, according to the System Info, although delivered in late October 2014; 32 gigs of RAM) running OS X Yosemite v 10.10 all the Microsoft Office 2011 apps run fine and the apps show up in Recent Items under the Apple menu, but no MS Office documents do. Documents created in all other apps do appear in Recent Items, including a couple of Word and Excel files opened, renamed, and saved using Pages and Numbers, respectively.

I spent about an hour on the phone with an Apple Care rep and a supervisor/specialist, neither of whom could figure out what was going on. As recommended, I reinstalled Yosemite (no help), and on my own deleted and reinstalled Office 2011, going through all the online updates. Again, no change.

I trashed the plist for Recent Items (no help) and then removed the recentitems.plist.lockfile, which was there to the surprise of the specialist. From what I have read, its function is to keep the system from getting confused or overloaded if two programs are trying to write to the plist at the same time. A new recentitems.plist.lockfile was not created after I took it out of the Library/Preferences folder.

I really don't want to do a clean install an d

Any thoughts? This is not a critical flaw, but it is annoying.