First I'd like to confirm your observation about the beep after the update. Indeed its gone. Also I notice that pressing F10 will present the bios not the boot menu. I did not investigate this further.
Another observation that I'd like to add after the update is that the options in the bios seems to be animated (if selected and not yet pressing the enter key). It only dissappears after several reboots and setting the bios configuration to defaults. Another one is when reverting back to a lower version causes the screen to remain blank with the cursor blinking at upper left of the screen and not booting to the OS and not even to the bios either if you press F2. This is reported earlier in other threads. I am successful to revert back to 0310 after some unusual procedure. With 0310 everything is back to normal.
Same thing happened here. The POST beep missing doesn't really bother me, but since one of the BIOS updates probably about 6 months ago or so I have not had success being able to reliably access the boot menu during startup. Usually what happens is I mash the F10 key as much as possible, no boot menu, CTRL+ALT+DEL and try again, usually to no avail. This is very frustrating; does anyone have an idea as to what might be going on here?
312 is really a defective bios revision. I have revrted back to 251 which is table enough.