Odd DeathAdder issue

So a bit of background, I've been playing counter-strike for quite a while, and as soon as I got a bit more serious with the game, the only mouse I've really ever used since maybe 2004. Well since then my mouse settings took a few turns but eventually I settled on one common sort of setup. This setup being- Mouse Settings: 1800dpi, 500hz. Windows Settings: 6/11 . In-game Sensivitiy: 2.7. Usually with a CPL mouse fix to fix the acceleration. Well anyways now the problem i'm having, I just recently bought a new rig, going from windows XP, to Windows 7 64bit and i've noticed a really annoying issue with my deathadder. This issue being 1800 dpi is almost unusable that it's so fast. I've tried lowering the dpi to say 450, but the settings usually don't feel the same and it makes me just awful at games. I've also tried solutions that mess with my mouse accel, generally it doesn't really seem like mouse accel is the problem. It just seems my overall sensitivity is fucked. So i'm just wondering if anyones ever had a similar issue, or if there are any solutions. Just anything at all really, pretty tired of playing games so gimped.
Here's my current setup if it helps:
OS:Windows 7 64bit
Mobo: MSI P67A-GD65
CPU:I7 2600k
Graphics card: GTX 560 TI