The tmp files should be I the same folder you normally save your drawing to.
See if this post
and this post
, helps you situation, i.e. check if there are any dwl files showing up when TC is closed, they should be in the same folder you normally save the tcw file.
Other posts are more drastic, if the situation becomes more permanent, like files are always saved as tmp. these posts suggest its may be a problem with windows user account, I personally have not seen the problem you encountered, so I cannot say this will cure it. see This thread
and this thread
, both point to UAC problems.
But if your problem is just once or twice a month its probably unlikely to be UAC