I recently had a user clean up a lot of pictures on their computer by moving and deleting them.  The next time the user went into Office Picture Manager, the splash screen would appear but it would never bring up the program (never meaning within 5 minutes - I have read reports that it will eventually open it just takes time).

The problem seems to be the catalog file that OIS.exe (the Picture Manager executable) uses.  Follow these directions to reset the picture manager catalog:

Browse to %userprofile%\Local Settings\Application Data\Microsoft\OIS. Locate the file named OIScatalog.cag, and double-click on it. When asked what you want to open the file with choose Notepad from the list. When it opens you will see a file that looks like the following. Remove any lines that start with mru path. Make sure to remove the entire line including the opening/closing tags. You can also just delete the OIScatalog.cag file, and it will be re-created the next time you open a picture.