Go to your username>library>preferences and delete:
Adobe Photoshop Elements 11 Paths
Adobe Photoshop Elements 11 settings
and any lockfiles with the same names. That library is hidden in 10.8. To see it, in the Finder click the Go menu and hold down the Option key. It will appear below the little house for your user account. While you are in there go to the saved application states folder and delete anything in there for PSE.
The File->Open Recent files show recent files list. If you are talking about files automatically reopens in PSE then there is an option on Mac under Settings->general which says "Restore..."
Also found an issue with 10.8 here http://forums.macrumors.com/showthread.php?t=1326035
Please see if it helps.