Plz make sure you follow the correct flash procedure ( as Stasio already mentioned) or get stuck with my the double post bug again
1. Reset your UEFI to Optimized Defaults, reboot, enter UEFI and then flash to the new UEFI build.
2. After flash and restart, shutdown the system before you enter Windows/Linux.
3. Remover the power cord from the power supply, wait thirty seconds, press Power On button to clear any remaining charge, clear CMOS for five seconds, reattach the power cord, power on the system, enter UEFI, set to Optimized Defaults, save and exit.
4. Enter UEFI, set your system to customized settings based on your system configuration (RAID, OC, etc), save and exit.
Especially the cmos reset is important, as my sabretooth was not posting ( again), after the cmos reset it finally works as it should...