I'm running two 7870 XT's in crossfire and had no issues until I played some older games and a newer game that didn't work properly with crossfire. I went into the CCC and disabled crossfire and everything was fine; I go back to turn it back on and it just won't enable. I check Enable Crossfire pick apply and it goes to Disable Crossfire I've tried switching it in both the Gaming Tab and Performance Tab, am I missing something?