You are going to delete the .cdx files in the database, the .cdx files are the thumbnails files the database generates and they can become corrupt therefore we can delete them with out effecting any database information, The steps for that are as follows.
(only do one of the steps 2 - 6 depending on which software & operating system you have)

If you feel uncomfortable doing this, I would recommend making a copy of the Default folder before proceeding.

1. Close Photo Manager.
2. If you have moved your database to a somewhere other than the default location, please go to that location. If you haven't moved it (and you would know if you have) then select the default location for the correct version and operating system.
3. In Version 9 on XP: In Windows Explorer go to this location: "C:\Documents and Settings\YOUR_USER_NAME\Local Settings\Application Data\ACD Systems\Catalogs\90\Default"
4. In Version 10 on XP: In Windows Explorer go to this location: "C:\Documents and Settings\YOUR_USER_NAME\Local Settings\Application Data\ACD Systems\Catalogs\100\Default"
5. In Version 9 on Vista: Go to this location: My Computer, C:\Users\[Your User Name]\AppData\Local\ACD Systems\Catalogs\90\Default
6. In Version 10 on Vista: Go to this location: My Computer, C:\Users\[Your User Name]\AppData\Local\ACD Systems\Catalogs\100\Default
7. Once you are in the correct folder:
8. Go to View | Details
9. Click on the Type column header to sort the files by type of file.
10. Select all files that are listed as cdx files and hit the delete key.

Tip: Make sure you go to YOUR_USER_NAME\Local Settings\Application Data. There is a YOUR_USER_NAME\Application Data and that is the wrong one...

Tip for On XP If you cannot view the Local Settings folder

Tip for On Vista If you cannot view the AppData folder

If you can't find the cdx files and you are sure you are in the right folder, please look at this screenshot. You want to select all HIGHLIGHTED files and delete them. DELETE only the highlighted ones in the screenshot and leave the others.