Avast antivirus, which I had been pretty happy with compared to AVG has begun to report false trojan horse messages with their latest update. Soon after the update, I started to use Copernic, and I got the horns a'blarin' warning message, so not really paying attention to what might have been the problem, I told Avast to move the offending file to the chest. Then I went to use Copernic, and surprise, surprise! It wasn't there anymore.

Avast had very nicely tucked my Copernic exe file away in the virus chest. An attempt to reinstall was stopped in its tracks as well. Users reporting in the Avast forum say that it affects any number of programs. http://forum.avast.com/index.php?topic=51607.0

The message reports that Win32:Delf-MZG [Trj] has been found in multiple programs apparently, though the only one that it has disabled for me has been Copernic.