This is interesting. Do you trust the SAT to IQ estimation site? Because according to those I'm at 150 when I thought I was at 144:

1450 [GRE]
146.92 [15 SD]
150.05 [16 SD]
99.912 [Percentage]
1440 [SAT]
148.42
151.65
99.938

Suddenly this makes sense. I think the more I focus on something -- especially when I'm forced to perform in an exam environment -- I do better. The 144 IQ was during a meeting at work maybe 20 years ago when I was bored and I was focusing a lot but not at full power. I've had 140's when trying for Colloquy but that was even less focused.