trojan win32/FaveAv.CX detected by antivirus app in 2.0.0.15,

my antivirus program at work today detected the trojan win32/FaveAv.CX
in the installer program Firefox_Portable_2.0.0.15_en-us.paf.exe
and in the executable that's created or extracted by the installer.
It also happened to 3 others.
It was detected by computer associates etrust InoculateIT with signature 31.6.6037
on client version 6 and version 7.

I've scanned the Firefox_Portable_2.0.0.16_en-us.paf.exe and that comes up clean.

What's the deal? Is there really a trojan in it or is it a false alarm?