Cpu overheating problems

I have an epox 8kha+ motherboard and an oem Athlon XP1800+, is it normal for me to have a cpu temp > 45C? I've tried using programs like CPUIdle Pro to lower the temp when the CPU is idle, but now it's not working. I have a Thermalright SK6 Copper heatsink and a regular sized fan on it. Do you think I installed the heatsink incorrectly? Or maybe I didn't put enough thermal paste on the diode?
dude you can add too much heat grease way easier than too little. also amd's usually run quite hot(reason for their lack of thermal protection) so its prolly just normal cpu temp.
I don't think that's true, I've read that XP1800 with retail heatsinks should have an idle temp of around 27C, but mine is 49C. I'm not overclocking either, and my cpu usage is 0-10%.
i dunno every single amd i ever had was hot sob they tend to melt. for example my amd k6-2 running at 500 stays around 43-47 and my celeron oc'd from 366 to 550 runs at 32-36.

so its all really just how well your chip is made. zzz
Ok, you seem pretty high to me for most typical AMD processors I've seen running actually...too close to the average 50C limit.

What brand of thermal grease are you using?

Be sure to use put a very fine and thin layer of grease over your the die of your processor, I would use a straight edge razor blade, a credit card, or something with a straight edge to make sure you get an even layer on it.

Also, how's the ventilation in your computer case?

If you don't have good air flow to help dissipate the heat from your case, then you will experience higher cpu and system temps regardless of how good your heatsink and fan maybe along with the thermal grease.

I would recommed you re-apply some thermal grease again, and make sure you have good air ventilation, probably install some system fans if the air flow is not so good. I've personally shaved close to 10C off my processor temp by simply buying a better computer case that had good air flow and two system fans for in-take and out-take, goes to show how important good casing is.

Hope that helps you lower your cpu temps.
You also might want to try a new heatsink/fan combo, you could try a copper swiftech with a delta fan. It may be a bit loud, but it WILL cool you down fast.
I've got a Swiftech 462 copper h/s with Arctic Silver II thermal paste and an 80mm Delta Screamer Fan, as I'm typing this my core temp is 36 on my Duron 800. With the standard HSF fitted it regularly went over 50, now even when I give it some hammer I think the highest it's been is 42, which was in the summer when the ambient temperature of the room is higher (makes a surprising difference!).

SkankinMonkey has a point tho, if the PC is in your bedroom and you wanna leave it on all night, forget about sleeping - the Screamer makes a right racket.
try a Coolermaster or a thermallake volcano cooler. If that doesnt work i'd look into water cooling and pelters
I let my friend replace my generic brand thermal paste with his Artic Silver III, it seems to do the trick... the highest temp it reaches is 45C.