Q6600 high idle and load temps

I bought a gateway GT5628 a year ago and have had a lot of problems with it. To start with I had to get the graphic card replaced 4 times (8500 gt) and then i finally just bought a 9600 gt. I've also had to reformat a couple times do to system error. A few days ago I downloaded speed fan and am very confused on what it is reporting:

idle temps in C

gpu-55
cpu die- -42
motherboard-44
ICH-84
MCH-76
HD0-42
core 0-54
core 1-50
core 2-52
core 3-49

cpu fan-1351 RPM
chassis outlet-1718

These temps seem waaaay too high, and the fans NEVER increase when the system is under load and it gets really hot.

load temps in C

gpu-65
cpu die- -30
motherboard-49
ICH-84
MCH-78
HD0-42
core 0-72
core 1-68
core 2-70
core 3-69

cpu fan-1321
chassis outlet-1732

It kind of worries my that the cpu fan actually slows down under load instead of increasing. Anyone have any clue as to what is going on here?

Motherboard is a intel G33, rest of the specs can be found by looking up the model number above, only modification i have made is changing the graphic card.

I just used intel thermal analysis tool and set the work load to 100% on all cores. Finally at about 80 degrees the fans increased in speed (cpu 3400rpm, outlet 2200rpm) this seems like kind of a high threshold for the fan to kick in, is there any way to lower the temp at which the fan kicks in?

Probably the fan. The fan might need to be reseated as well as get some new thermal paste.

Also if you can, see if the case would allow for a better aftermarket fan. The stock ones are pretty much crap.

And check the current fan for dust and make sure the airflow is good.