I can tell you that it's not normal behavior.
I have the same motherboard, a "K" model 3770 CPU, but I'm using the integrated video. Windows 8 Pro. Sleep/wake works as one would expect...tap on the mouse, the power LED goes solid, the disk activity light flashes and the screen comes up with Windows where it last was.
To me, it sounds as if the BIOS is reloading default settings because it believes the setup info is incorrect or corrupted. If that's the case, check to make sure:
-- the 3V CMOS battery on the motherboard is good and properly seated
-- the 24pin ATX and 8 pin E-ATX power connectors are _fully_ seated in their respective sockets. Same for the 6/8 pin power connectors for the video card (if used).
-- all the USB headers on the motherboard and any device attached to a USB port are secure
The next thing I'd try is to enter BIOS setup, select "reload defaults" and then save the setup and exit. You can test the sleep behavior at this point to see if it operates properly. If so, you can reboot into BIOS setup and set your preferences and retest.