ASRock recently released a beta BIOS (version L1.85) for the P67 Pro3 board. You can find it here. Note that it is only usable for the Instant Flash method (loading the BIOS file onto a USB flash drive and going into the BIOS to flash it from there).
My review of the beta BIOS:
----- Changes that I have noticed:
1. Double-boot issue has been fixed.
For me, both the B2 and B3 versions of the board had problems with cold booting (power on for a few seconds, power off for a few seconds, power on and boot normally). This happened at stock settings and while overclocked. With the beta BIOS, it no longer happens. Yay!
2. Lists single- or dual-channel memory mode in first BIOS screen.
This is good info to have to make sure you have the memory in the correct slots for maximum performance.
3. Load Line Calibration setting remains visible if CPU Voltage is set to Offset Mode.
This setting used to only appear if the CPU multiplier was left at Auto and the CPU voltage was left at Auto. If either of those settings were changed or the Load Optimized CPU OC Setting was used, it would disappear.
Problems I have noticed:
Further improvements that could/should be made:
1. Should list single- or dual-channel memory mode during boot process instead of having to go into BIOS to see it.
2. Should list memory speed during boot process instead of having to go into BIOS to see it.
3. Load Line Calibration setting should remain visible when CPU ratio is set manually, when Load Optimized CPU OC Setting is used, and also when CPU voltage is set manually.
If anyone else tries the BIOS and notices any other changes or problems, or has any suggestions for improvements, post here. Maybe ASRock will take note...