HP MCP61PM-HM (Nettle2) 5.27 With Unlocked Overclocking Options

[Indead]

After flashing the bios on my Nettle2, the rear case fan went extremely loud, and started making a very loud grinding sound after about 5 minutes, the center of the fan was warm to touch.
I unplugged it but I would like to fix it soon, as my GPU is heating up my case far too much if I put the side panel back on.
What should I do to fix this?

EDIT: I also tried using speed fan to slow it down, but that program did nothing, except confuse me.

I have the exact same problem as jsilver, and I have tried the exact same things that he has. The fan is way too loud, so I unplugged it but the CPU seemed very unstable, I went in with Speedfan and tried to reduce it's speed, but again, it didn't even respond.
So far this new bios hasn't really worked out for me, my computer now studders in odd places, I can't even get the machine to play music off of Windows Media Player anymore without the program "not responding".
I was able to hit the 800mhz on my ram, so that was nice, but with this studdery juttery, programs crashing all of the place performance, I can't even try out any new speeds for the ram or the CPU.
Someone please help me if you can.
Just so you know I'm using the AMD 5000+ with the stock 2.6 GHz, 8GB of DDR2, Windows 7 Professional 64Bit, also, so you know I went it and enable that one option in the bios that recommends the user able if they have a 64bit OS.
Unfortunately, even at the stock 2.6 cpu speed and the RAM's speed set to auto, i still get these jarring hitches.