Screens blank after 5 minutes, despite power settings.

[Trick Question]

The power settings for my Windows 7 64-bit workstation are: never blank the screens, and sleep after 3 hours.

Avira is not doing anything to blank the screens (you need Pro for that, and I checked).

The monitors (three) are LED ViewSonic. They don't appear to have any settings that would cause them to blank out.

I can't figure out what's causing this and it's driving me crazy. Any ideas on how to stop my screens from going blank? I'm going to have to use a Caffeine solution, and it irritates me that I have to send signals from the keyboard just to keep the monitors viewable. I suspect it's Windows doing it but I don't know how to be sure or to fix it.

 

[Trick Question]

Addendum: I've also checked AMD Catalyst Control Center. I can't find any options that would cause screen blanking there either.