Heatsinks lapped + AS5, no improvement. Ideas?

My air-cooled temps are nice, but I lapped my heatsinks and applied new thermal grease hoping to drop them even more. I replaced the thermal greases - there were white thermal greases and some kind of dry white adhesives - using 99.9% Isopropyl alchohol for cleaning followed by Arctic Silver 5.

I used the sandpapers with the folllowing grits: 220, 300, 400, 600, 800, 1000, 1500, 2000. I just used standard sandpaper, aluminim oxide I think. The final 2000 grit sandpaper doesn't seem fine enough, it left clearly visible lines on the heatsinks. It wasn't really like a mirror, but I could see a clear reflection if it was held against paper at a very small angle. Would using water help?

I think after all this it didn't help my CPU at all, and my VGA is actually got slightly worse. I have no way to measure northbridge or southbridge so they could be burning up for all I know. I'm hoping that burning-in the CPU and VGA will help the grease set but I kind of doubt it will do anything.

Would 2500 grit sandpaper, orbital buffer, or some kind of polish help out? I actually tried using paste 5 times on my CPU. One time I tried it like ArcticSilver suggested - a line down the middle of the IHS between the cores (horizontal line when in my mothernoard) but my CPU temp shot up to 65 on bootup. Slathering the AS5 on seemed to work as well or better than other methods; the excess just gets squished out and it must be joining the surfaces well because one time it took a LOT of force to remove the heatsink from my CPU after this.

My system:
-Intel Core2Duo E6600 2.4GHz with Thermaltake BigTyphoon,
ruining at 3.2 GHz, 1.3125 BIOS volts, 1.24-1.27 real volts, core temps at 23C - 45C (TAT)
-ASUS P5B Deluxe, 266 MHz but running at 400 Mhz (1600 FSB rated), max motherboard temp 26-30C under Orthos
-ATI Radeon 1800XL 256 MB (499/495 running at 567/567), cooled by Zalman 9700-Cu to 38-45C.