First of all I LOVE CCleaner! Thank you for your work.
CCleaner needs to clean the Windows Media Player Transcoded Files Cache directory.
It's under C:\Documents and Settings\User\Local Settings\Application Data\Microsoft\Media Player\Transcoded Files Cache
Had discovered about 1.6 GB of TMP files hiding in this folder.
I made sure Windows Media Player was CHECKED under the 'Applications' tab.
-D