Digital BW, The Print

I've been bouncing around the web getting no good answers on this so I though I'd ask it here, with all the PS users, some probably sporting dual monitor setups with Macs. My second monitor began getting hard to wake up, and would flash, or start dim, etc. before waking up in the AM. Now, I can't seem to get it to come on at all, though it will flash a bit when switching "mirroring" on and off...
It's been suggested my graphics card can't power both well, sounds reasonable but I'm not sure why it would drive both at first, then slowly fail. I can't recall how I tested this, but it doesn't seem to be the monitor itself.
Anyone know anything about this? There seems to be similar questions all over the web, and no expert replies.
Thanks, Tyler

John, we're on our way over with your meds