It\'s more likely that the file in question was locked at the critical moment by a virus checker, so the program couldn\'t delete the \'old\' file.
Norton is notorious in this way, and possibly others.
The trick here is to exclude ALL of the BOINC folders from both automatic and manual scanning.

AVG, Ad-Aware, and Spybot, are NOT problems in this matter.

I KNOW that the file isn\'t a .txt file, but it IS used just for storing DATA.

You\'ll continue to get warning messages until you exclude the BOINC folder from scanning.

A second problem with some AVs, e.g. Norton Anti Virus, is that they lock each file before scanning.
The program is a massive supercomputer based program written in Fortran, and the code doesn\'t like being denied access to it\'s files when it needs them. So the model crashes.

I haven\'t heard of your AV before, so I don\'t know anything about it.
AVs and virii have been talked about in the past on our php board here.

yabfg.aswap is a text file, not an executable file. It CANNOT contain a virus.
The situation you have is called a \'false positive\'.
One AV program,, Sophos, keeps finding it, and automatically deletes the file.
This causes the program to crash.

There are two cures:
A) In the options of the AV, exclude the entire BOINC folder from scanning.
B) If it is Sophos, update to the latest version, which is supposed to be fixed.

Then reload BOINC from your backup.