Zip up the memory dump files and upload them with your next post. They're usually located at C:\Windows\Minidump
Reset your BIOS to default values, and ensure that you have the latest version of the BIOS (this is no guarantee, but it may help). If the system doesn't crash then, then you've found your culprit.
Finally, most sleep errors occur due to video drivers
. Get the latest version from the manufacturer of your video chipset (ATI, nVidia, Intel, etc) and install that. FYI - I'm having sleep issues with my system and am starting to think that it could be a bug in Windows 7 and it's ability to work with system BIOS's.