Strange files / icons in preferences folder

One of your applications might be acting up - getting confused by something in the Preferences folder and making a new folder with a garbage name, for example.

The best way to track this down is to move your preferences to a temporary folder, then launch, test, and quit each application you have on your computer, checking the preferences folder each time, until you find the offending application. If that doesn't work, move your preferences back, then try this:

Move one application's preferences to a temporary folder
Launch that application, test it, then quit it
Check the preferences folder - did you find the bad app?
If not, put the file you moved back and try again with another application, making sure you keep track of which applications you've tested already.