I did a normal scan of my C:\ drive, and one of the errors in the log said:

C:\Documents and Settings\Myname\My Documents\My Videos\a-filename-that-ends-in-a-question-mark?.mp4: Invalid argument

I've only seen this once, so I will assume it's the question mark since I have no other answer for it. I really hope that it wasn't the question mark's fault, because that way, a virus could trick ClamWin by giving its filenames question marks.

is that file created in Windows or Unix based one?

hmm it's a non ansi char, are you sure the error is exactly the one you posted?

I suggest you get an MD5 hash of that file, and do a search on Google to see what you get. If you scan it with Jotti, you will get the MD5 hash--just copy it and search.

Regards,