What driver version?
I've had similar issues with Win7 desktop, seems the OS simply doesn't detect it propely (can't read EDID for some reason). As the drivers progressed out of beta, it got better, but varies issues pop up now and then, also with my TV (which is a CRT though).
You could try to find an .ini from Crysis that details your res settings and force it to 60Hz there, but I'm not sure that's a proper solution.