Well stranger still, I downloaded the 1.0.7 version of firetune it took several attempts using several different download mirrors but I eventualy managed to download it. I scanned the installer firefox.exe file and no warnings at all.
I tried to install it to see what would happen when it was installed (unpacked) and all I kept getting was a CRC error.
Will have to download again and reinstall firetune 1.0.7 or revert to 1.0.6.