If you're not happy with your CPU temperature. Then try to change the thermal paste with a better one and reset the heatsink properly back into place. If the CPU temperature remains the same then it should be ok.
I have the same issue with my P4 system when I replace the heatsink/fan, I was not able to place the heatsink properly and the temperature 7 degre higher than the stock.
So you might have to double check on that or check your CPUs thermal spec, it might be that is normal as well.
engineering defect in stock Intel heatsink/fan units
for LGA-775 socket CPUs
(This generic message only applies to
Intel CPUs with LGA-775 socket and
stock Intel heatsink/fan units.)
The problems with high CPU temperatures
are most probably the result of improper seating
of the stock Intel heatsink/fan unit ("HSF").
That heatsink and fan do dissipate heat quite
adequately, as long as the HSF maintains
enough downward pressure on the top of
the CPU chip.
the 4 pronged fasteners are not gripping properly,
and this results in less downward pressure on the
top of the CPU chip: less downward pressure
translates directly into higher CPU temps.
Also, the fasteners are made of a material
that appears to be "creeping" after many cycles
of heat and cold, which further reduces the
downward pressure on the top of the CPU chip.
A short-term solution is to unlock and re-lock each
fastener, while pressing down with your thumb on
the fan housing directly above each fastener.
Doing this one thing reduced our CPU temp from
140 F. to 100 F., which helped isolate the problem.
Best solution is to switch to a superior HSF
with a proper backing plate. We prefer the
ASUS VR Guard Series, because of its superior
engineering for cooling the voltage regulators
on recent high-end ASUS LGA-775 motherboards.
These photos show evidence of improper seating
on a recent ASUS motherboard with stock Intel HSF:
Also, Intel's Thermal Interface Material ("TIM")
is too thick from the factory, which also results
in improper seating i.e. all 4 pronged fasteners
do not "lock" properly, even when applying a
lot of downward pressure on each fastener.
This TIM should be removed and replaced with
a razor-thin layer of Arctic Silver (or comparable
thermal paste) -- NO OOZING PLEASE!!
I hope this helps.
p.s. If you purchased your computer from a company
that uses Return Merchandise Authorizations ("RMA"),
you should start a new RMA so that this defect and solution
are reported formally to your supplier.