This can happen if Replay Media Catcher's data files become corrupt. Here's how to re-create the database files:

1. Close Replay Media Catcher

2. Remove this folder:

Windows XP:  C:Documents and SettingsApplication DataReplay Media Catcher 4

Vista/Win7 C:UsersAppDataRoamingReplay Media Catcher 4

3. Restart Replay Media Catcher and the files will be re-created.