I'm experiencing the same type of symptom, console redirection works up until the menu starts then takes no imput.  Upon reboot I see:

"vidcontrogetting active vty: Inappropriate ioctl for device"

then the normal shutdown process.  I tried the enabling and disabling then reboot method and got the same results.  I have the box connected to a Cyclades alterpath 16 (I know there is some weirdness with these devices running certain firmware).  I just wanted to verify that if this is a known issue or just simple user error before I go digging any deeper.

Some possible useful data points:
This was a new install of BETA4
Hardware is Dell 2850
Console redirection is "on" in bios but disabled after BIOS (so the OS can take over). 
I see what I expect up until when the menu is supposed to be there. 
The menu appears on the VGA monitor I have plugged in and the keyboard works. 
/boot.config does have -D in it. 
The cyclades does work for all the other devices plugged into it.