Excel creates a bunch of .tmp files in the Windows Temp folder. If you're
seeing them in a different location, it may not be excel (I've never seen xl do
this).
It may be your antivirus program.
One person posted that they saw files that had names like: ~RF26c83af.TMP.
It was caused by AVG.
You can read her description in this thread:
http://groups.google.co.uk/group/mi...ct:autorecover"&rnum=2&hl=en#cccd4eed0638e395
or
http://snipurl.com/jyus
A while ago, someone posted back that uninstalling something called "Panda
ClientShield" fixed a similar problem.
Even if you're not running "Panda ClientShield", you could try disabling this
program to see if the problem goes away.