I've installed this model on p4 2.8 @ 3.15 a week ago and I've noticed two things:
1. The general temps stayed the same as with the Intel stock cooler and perhaps even higher!
2. Every few seconds there is a +10 C peak. (if the temperature is ~50 C then every 3-4 seconds it will be ~60 and then back to 50)
What would be the cause of that?
Should I be worried? 8O
Hmm, that should be a really good cooler, I had it on my 3800+ for a couple of years. Is the fan seated well on the processor? I have heard that thermal paste can take a little while to set, so it may stabilize after a while. Are you running the fan at full speed? Those temps don't sound too high, so no need to worry too much for now.
70 is a little high, but far from dangerous. I believe those P4s always ran hot, so I wouldn't worry. That zalman fan is a good fan, so it will provide adequate cooling. Does your case have good airflow? What are the ambient temps?
I wouldn't worry about it, if you have a good fan (which you do), any themal paste (again, you do), and good airflow (you now do), then I would say it is safe and your MB sensors are wrong. When you said temp jumped 10C, I had a feeling that the sensors may be bad. With a big HS like that, temp jumps should be in the 1-2C range. Even a hot processor can't heat a big block of metal that fast.
Of couse, you can try the other thermal paste just to see if you can lower the temps, but I doubt it will do anything.