Asus P5N-D Heat Problems

Asus P5N-D
Intel e6600 @3.2ghz (400x8 FSB)
BFG Maxcore 65nm OCX Nvidia 260
4gb ram Corsair XMS2 DHX @800mhz 5-5-5-18 timings
X-Fi Fatality
Swiftech Watercooling system
Vcore 1.39v
Nb 1.36
SB Auto
Windows Vista 64-Bit

I had temps around 35'C Idle - 45'C Load BEFORE. I have a heatsink on the NB with a fan installed on it. So lately I've been noticing that my motherboard temperatures are now getting really high (42'c Idle - 55'C Load) The P5n-d never got this high before even while overclocking. So I took the first approach that came to mind. Take off the heatsinks remove all the old thermal paste and put new paste on (Arctic Silver 5) This dropped the temperature about 2-3'C (from 45'C-55'C). Why is this happening?

Is this normal with this board? .

CPU runs at 23'C idle - 29'C load.

I checked the temps using the bios' "Hardware Monitor"

Just purchased a intel q9550. Will this help my motherboard temps at all?

Thanks for your time