I had problems coming out of sleep mode after overclocking adjustments done through Auto Tune.
Looked into it and fooled with some BIOS settings, ultimately going back to the factory settings, and then tweaking from there. But I must have messed something up, and started getting an AE (Legacy Boot Event) on the diagnostic LEDs. It would finally boot, but it would sit there for 30 to 45 seconds.
Google search showed people saying the boot order was messed up. I fooled with it several times, finally getting it to boot normally with every other boot device disabled (except the DVD) and the main HDD as the 1st boot device. I disabled all other drives.
Worked for me. Normal boot and sleep mode works.