5770 overclocking issues

[Win7]

I had my 5770 overclocked to 925 and 1410. It was stable with the ATI Auto Tune and Crysis. Then when I played COD4 it froze, so I backed it down to 920 and 1395. That still made COD4 freeze, so I went all the way down to 900 and 1355 which was working fine until Half Life 2 froze. My temps never go above 55C and even though my powersupply is only 500 watts and is getting really old, it handles it without OCing with no freezes at all. I'm getting a new PSU, the Corsair 750w(FTW!), and I'll test it out then, but whats wrong? I've read about it being as oc'able as 950 and 1410! Also at one point the ATI auto tune actually got it up to 950 and 1425. Is this weird at all, or is Half life just bugged up a bit?

EDIT- Is there any sort of ratio that has to be maintained between the core clock and the memory clock? And I am oc'ing via the Catalyst Control Center.

[kckyle]

were you trying to run it in eyefinity?

[Win7]

Nope, not yet.