<< i'm using the stock fan on a 1900+ until my 8045 comes in the mail. i was checkin my mail and my temp jumped 7c! what happened!!!!! >>
Assuming your checking proceedures are identical (full load vs. full load, or no load vs. no load), and you are using the same equipment and program to give readings it only leaves the HSF to check out. I just installed an aplha 8045 and mine jumped 2C after using it a bit. I can only assume that the arctic silver 2 compound I used has shifted a bit with the temps and is slightly less effective. In the first couple of days after you install a HSF you can get different readings and this would be normal. I wouldn't think a 7C difference could be the result of anything like this, even with a stock HSF. Make sure nothing has shifted or come loose on the cooler.