AMD Display driver keeps crashing on some of my cards at random

I had two Sapphire 3L 7950s in a Crossfire board for a couple of weeks, using GUI miner mining LTC with Windows 7 Ultimate. Everything ran smooth no problems.

Now I got two 4Ls to go with those, along with an Asus p8Z77 board for 4x Crossfire. The last several days I would notice decreased hashrates from time to time, and see that at least one of the cards was running 0 percent and not hashing until I stopped/started the corresponding worker on the GUIMining software. It seems that within a few hours at least one of the cards will go down. Very annoying since I cant watch it 24/7, and every morning since running 4x cards one of them has been down for a few hours while I slept. My temps range between 55-75 depending on the card, not ALL that hot...

Just now I noticed one down, did the stop/start to get it going, then a couple seconds later I got an AMD Display Driver failure prompt window, the screen flickered for a second, and that same card was back down again. This is the first time I have actually seen this happen, so I assume this is what is making the cards go down randomly. What should I do? Is this a known issue? I have the latest offical AMD Drivers. I dont use crossfire bridges. Please help. The current difficulty of coins in general is making profits slim enough, but I am having several hours combined of downtime every day since going 4x 7950s....