Macs Won't Forget Refresh Rate - LCD Refresh Out of Range

Question

I have a new Viewsonic LCD for an old G4. I had to use an ADC to DVI adapter.
The first time I booted up my Mac, the monitor worked fine. I went into the Display Preferences and, like an idiot, I selected 90 hz because, like an idiot, I thought 90 hz was better than 60 hz.
My screen went black and the monitor said "Frequency out of range", etc. I have talked to AppleCare and I have tried everything and nothing I do gets this Mac to revert to 60 hz at 1280 x 1024.
Tried zapping PRAM, didn't work.
Tried booting into Safe Mode and selecting another resolution. I do that, reboot, it reboots in that lower resolution. I select 1280 x 1024 and my screen goes black because it's going into that 90 hz.
Created another account, didn't work.
I plugged in my old CRT into the VGA port. I was able to select 1280 x 1024 at 60 hz. Turned off the Mac. Plugged in the LCD. Turned the Mac back on and it went black.
It does this when you log in. The actual bootup is in 1280 x 1024 60 hz. I get the login screen fine. It's when I log in, into any account, it goes back to that 90 hz mode.
In Windows, if you select a resolution or refresh rate, a dialog comes up asking you if this mode is OK and if after 15 seconds you don't click on anything, it reverts back to the original resolution. Apple doesn't want to do that, I guess, because they want me to use their monitors.
Any ideas?
Thanks!

Answer 1

You should probably just trash the preferences file(s). That will give you a fresh start with the Viewsonic. See this thread:
http://discussions.apple.com/thread.jspa?messageID=3308488&#3308488