Avast says Silver Chaos is infected but cannot find the virus

Hello everyone, I hope I posted this in the right place.

I downloaded Silver Chaos using sayuk's links in the game download thread, but when I want to unzip the folders, Avast says BGDATA.com, BGMDATA.com, CHRDATA.com SCRIPT.com and SEDATA.cm are suspected to be infected by Win32 evo-gen, and moves them to the Virus Chest. When I go there, right-click on one of the files and select "Scan", Avast cannot find anything. Has anybody else gotten this problem before ?

Here's a screenshot for clarity : http://i77.servimg.com/u/f77/17/98/89/47/sans_t15.jpg
Sorry it's all in French. "Scan terminé" means "Scan finished", "Zone de Quarantaine" is "Virus Chest" and "Pas de Virus" means "No Virus"

Thanks in advance

Chances are that what you're seeing is a false positive: Avast is seeing something that looks like it might be that virus, but when it takes a closer look, it realizes that it isn't there after all. Unless other files on your computer start being reported as having this virus, or someone else has the same problem with a different antivirus, I wouldn't worry about it too much.

If you're really worried, use an online virus scanner not related to Avast to check the files and verify that they're clean.

Apparently, Avast is prone to false positives with this particular virus:
Alerte Avast - Site Suspect + Programme Suspect - GMS Temple (en Français)
Avast! and Win32:Evo-gen report - PC & Mac Hardware and Software - Digital Spy Forums
Avast reporting scrrt.exe infected with Win32:Evo-gen
Win32:Evo-gen [Susp] Virus in 9.0.3 ... - DbVisualizer Forums

(and that's just from the first page-and-a-half of Google results . . .)

Thank you very much ! I'll check them with another antivirus, then.