Prescott too hot 64C

hello,my first post here
my system is as follows:
::GigaByte GA-8GPNXP DUO (not overclocked)
::Intel 3600mhz - 560 (1mb ache,800FSB) (not overclocked)
::stock cpu fan
:ne fan attached to the case
::a fan attached above the northbridge.
::and a D.P.S that has a heatsink.
:; the case has an airfilter like intel is suggesting.

the system at the moment has a temperature of 64C and during a heavy load it could reach 80C easily.
I was thinking of getting a" Gigabyte 3d Rocket cooler" but since the PC has not crashed only 2 times but i bleieve it's due to my 3d card X600pro
(running this pc now for almost 5 hours).
do you think that the motherboard is showing me the wrong temperature?even though it's a new model compared to others.
what about using different thermal paste doesnt make a difference?
and how many rotations per mintue does the intel stock fan perfom?mine is doing 2557..I havent seen it reached 2600rpm.
I contacted Intel and they told me it rotates 5000rpm.

thanks in advance

your fine the temps are always way off and there isn't much heat can do to your CPU