New False Positive From Spyware Doctor?

After today's update, Spyware Doctor reported the trojan
backdoor.agent.air on 2 PCs today. In both cases, it appears it may
be a false positive which is triggered by our use of the antivirus
nod32 since the nod32 resides in that c:\Program~1\Eset\ directory
and, per the Sophos web site, one of the characteristics of agent.air
is that it creates c:\Program~1\Eset\iexpl0re.exe.

Has anybody else experienced this? What is the best way to determine
whether it's a false positive?

Thanks a lot for your help.

Trish