For the older, but still functional clipboard extension "ClipX" (tested with the 2008 x64 beta version and on Win7x64); it removes temp files which appear over time due to a bug, I guess (e.g. over 1 GB when I deleted the files today):
[ClipX*]
LangSecRef=3024
DetectFile=%LocalAppData%\ClipX\
Default=False
FileKey1=%LocalAppData%\ClipX\Storage|*.*