Zero kb files

Hi

I have this two files in "my documents" folder: CAHK3HP E CATCE1TN, both with 0 KB. I tried to see the files extensions, but they only show the dot (.) at the end of the file, without any extension. I tried to remove,rename, shred them both with Tracks Eraser Pro, without any results. I also tried to find them on dos without any success...
I have windows xp professional sp2, up to date, and Norton Internet Security 2007.

What could it be? Simply can't get rid of this two things...

Thanks.



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