I made a stupid mistake while messing with custom resolutions and now I'm stuck

I've been struggling to get my Cinema HD display to show full resolution on my hackintosh and used SwitchResX to change it to a 1920x1200, which should have worked. The settings were apparently not quite right and the screen went so black I rebooted, hoping the old settings would persist. What actually happened is I am faced with a black screen every time the video drivers load and sets the resolution to one that is unsupported. Connecting a different monitor allows me to use the machine but I can't change the settings of the Cinema display without it being connected, and every time the Mac detects it it sets the wrong resolution and it shuts off. If I connect two monitors at once it just shows the backup I am using.

I imagine there's some file somewhere telling the Cinema HD display to use a broken resolution at boot, but I can't figure out where that might be. I've tried uninstalling and reinstalling SwitchResX but to no avail.