Crossfire Idle Clocks

[Intel_Hydralisk]

I have 2 5870's in crossfire at stock speeds with 3 monitors. The primary card idles at 400/1200 which is normal for 3 monitors. The 2nd card SHOULD idle at 157/300, but it shoots up to and maintains 850/1200 randomly while on desktop. Is this normal? The second card is idling at 26 C so I'm not really concerned about temperature, but that's quite a difference in idle power usage isn't it? It seemed to be working fine yesterday when I first got the 2nd card, but now after booting it up the card won't go back down to idle clocks.