Dual-monitor setup problems

[Pants Dragon]

I got a Mac Pro with a 20" ACD last September, and I love it, etc, etc. I recently bought a 22" Acer monitor and am using them both to take advantage of the extended desktop feature. I have the 20" as my main display, with the menu bar, and the 22" on the right.

The problem I'm having is that if one of the monitors is turned off while the computer is on, and turned back on, the picture flickers from one to the other, going black alternately. The only way I've found to remedy the problem is to reboot my computer. Is there any way to fix this problem, or will I have to continue rebooting?

 

[mkrishnan]

When you say flickers, do you mean both monitors auto configure for the dual display? Or do you mean that you're stuck in a state where both monitors are not working properly? That's odd! I don't have an MP, but with other Macs I've used, there is no issue with turning monitors on or off while the computer is on, or generally with hot unplugging them.

 

[Pants Dragon]

It's hard to explain. Basically one will come on, then go black and the other will come on then go black, then sometimes they both come on for a second before one or both goes black. And they keep going on/black until I turn one off again, and then restart the computer while both are turned on.

 

[mkrishnan]

Wow, interesting... how are the two screens connected? Are they on ports of the same video card, different cards, etc? Does it matter which monitor is turned off, or do you get the same problem either way?

 

[Pants Dragon]

They're both connected through the DVI ports on the back of my Mac Pro. I only have the single base videocard, but it's supposed to be able to run two displays just fine. And it does, as long as the two monitors are on when the computer boots and they stay on. I'm fairly sure it does it either way, but I don't feel like testing it right now, the one that usualy triggers it is the Acer being turned off and back on.