First, this has nothing to do with the beta/pre-release (it's only a matter of the virus database), so please don't post about it into this particular thread.
Second, I checked the signature and I don't think there's anything wrong about it; maybe you ran the tool in the other OS and it was swapped from memory into the pagefile, but I wouldn't call it a false alarm (so I don't think anything will be changed about it).