I have an XP PC (Office 2010, a lot of other programs) that has a very strange problem. Lately, Windows\Temp gets filled with .flt files, ranging in size from a couple of KBs to to hundreds of MBs. EndPoint protection, Housecall, various anti-spyware programs don't show anything bad. Deleting the files doesn't do anything, they come back.
An interesting observation is that it seems that some of the smaller files are the group of bitmap images that keep repeating themselves multiple times. A user recognized them as part of either .pdf or .ppt file he got from outside.
Google search points to a Windows Search indexing. I will try to stop it but this is not a solution.