Hopefully this info will save people some trouble.

Installed the recently released GeForce 280.26 WHQL driver then noticed it bumped my GPU avg temp while playing FFXIV 10 degrees (from 62-65C to 75C). It also causes very frequent crashes (even blue screens) about 15 to 30 mins of gameplay.

My fix:
Rolled back to driver 275.33 WHQL, GPU temp went down and it works fine now. This is obviously an nvidia issue but has anyone come across this issue ?

My setup:
OS: Win 7 x64
GPU: EVGA GTX 460
CPU: Intel Q6600 2.4Ghz
FFXIV settings: 1920x1200 windowed, 2xMSAA, Drawing quality all at highest.