I recently built a system using an old Pentium 4 550 (3.4Ghz, 800 FSB, 1m cache) from my Dad's dead Dell Dimension 8400. I found an MSI board that supports this CPU (MSI G41M-P26). The original Dell used DDR 400 (PC3200) RAM and the Intel 925X chipset, while the new board uses the Intel G41 chipset and DDR3 (up to 1333Mhz). I bought 2 x2GB Patriot PC10666 (1333Mhz) DIMM's since they are readily available and much cheaper than 1066Mhz or 800Mhz DIMM's. DDR3 800 is very hard to find (only on E-Bay used). I'm also using an EVGA Superclocked GTX 550 Ti video card, an Ultra LSP650, and a Cooler Master Hyper 212+. The board works great and makes the system run much faster, except for 1 problem - the #2 temp sensor on the board runs hot, 40c at idle and 65c+ under load. No problem, you say, the G41 chipset is rated to 103c. Well, mine freezes the system every time it gets to 64c, requiring a hard reboot using the power switch. I'm assuming the #2 sensor is under the north bridge, but MSI provides no documentation for this and an MSI tech said that they don't release that info to end users (like Asus and Intel do). After trying different chipset coolers and adding fans, the problem was still there. Using only 1 DIMM didn't help either. I wasn't able to do anything processor-intensive, like gaming, video conversion, or benchmarking, without it freezing up. Even the automatic Windows defrag utility was causing it to freeze until I disabled it. MSI is ignoring my emails after the first one to usrma@msi, so I had to fix this one on my own. I finally installed a Delta AFC0912DE fan (from the Dimension 8400) on a homemade bracket, pointing towards the chipset cooler and RAM. This kept the #2 temp at 51c under full load, but the noise from this fan is unacceptable (63 dBA at 6000 rpm, 160 cfm, 2.5amp power draw). I installed a toggle switch so I can turn it off when not needed, but during gaming it's like a vacuum cleaner running right next to you. It's driving me crazy! I can't use a fan controller with this fan as it's PWM only and won't run at all with less than 12 volts. I could buy another fan with voltage control, but it would have to be at lest 100 cfm to do the job, which would still be too noisy. My question is; does this sound like a bad motherboard, or is the problem caused by the RAM being forced to run at 800Mhz by the FSB speed. Or possibly because of using a modern PCI-E 2.0 video card in the MB's first generation PCI-E 1.1 slot? Would switching to DDR3 800 solve the problem? Or is this board just a low-end piece of crap with inherent design problems - any help would be greatly appreciated.