I might suggest going into the BIOS and changing the "sleep" or "standby" functionality. Most motherboards support changing between S1 (POS) and S3 (STR) -- POS = Power On Suspend. STR = Suspend to RAM. Power on Suspend is where the system maintains full power, but the BIOS can down-grade the power usage. It saves less power than STR, but generally is friendlier to Windows if it has problems. STR is where the contents of RAM are saved by providing only enough power to keep the RAM on, while the other components all shut down safely. This is the more quiet, power-saving sleep that most are expecting, with the power light blinking usually. When you sleep the computer, which occurs? If the machine stays with fans going and all, it may be on POS, and switching to STR may help.
Alternately, you may have some device, or bad driver, which does not handle suspend properly. Some USB devices are notorious for being unusable or even crashing Windows from a suspend.
Since this is a brand new install, I hesitate to say try with a clean install of Windows, but it could be a corrupt install. Try removing all non-essential things from the computer (start with just HDD, optical drive, video card etc internally, and just keyboard and mouse directly into USB 2 ports on the PC), and see if it does it then?
Are you using wireless devices? Try wired.
Good luck and let us all know how it goes!