Overlay mode causes video not to display with radeon 9700 pro

[mach]

For some reason, when a video is rendered using overlay mode, it just displays blank. I have a radeon 9700 pro and have tried ati's official drivers as well as omegas latest radeon drivers. I don't remember it being like this before. How can I fix it?

[Asmodian]

Are you running a dual monitor setup? I have a 9700np and I can only render on the primary monitor using overlay mode.

[mach]

No, I only have one monitor.

[Asmodian]

A television counts as a monitor...
Otherwise I don't really know what could be wrong.

[mach]

I was looking around in the ati control panel and saw an overlay tab. When I clicked on it, all the settings (brightness, contrast, etc) where at -100% which caused the video to display black. Resetting them to default fixed it. I have no idea how that happened.