I recently upgraded an existing PC with an E6750 chip which I knows OCs to 3.8GHZ. I made a bootable memtest86+ 5.00 Beta USB using the file off the official site and plugged it into the board. This was used successfully in another PC. Initially, the system posted, but I could not get an OC anywhere close to 3.8GHZ. System would power off after BIOS changes, power up without posting, power down and power up again with BIOS defaults. Eventually, when I got to about a 3GHZ OC, the system posted, but I could not boot off the USB. It did not appear that the USB was recognized in BIOS as it was not under the list of bootable hard drives. After several attempts to boot, the system would hang on restart, right after it shows you the CPU FSB and multiplies but before it shows you how much RAM is installed in your system. Once I pulled the USB out, everything booted up fine. I also was able to get the 3.8GHZ OC without a problem. I never was able to boot the USB, but I created a bootable DVD and the RAM tested fine on the OC. System was also stable in Prime95. Never seen anything like this before, so I was just wondering if it is a known issue.