ThreatFire silently blocks Plants vs Zombies and other steam games from running

Apparently there’s an incompatibility between ThreatFire and steam. Trying to play Plants vs Zombies just results in it trying to load and then silently failing without any error messages. Simply disabling ThreatFire protection isn’t good enough; I recommend uninstalling completely.

There’s a forum thread on the issue – http://www.pctools.com/forum/showthread.php?t=65000