Occasionally fails to interrupt when rebooting

[Nancy Blachman]

Our 750 (running 4.2) occasionally does not reboot properly on an auto 
reboot.  Sometimes  the communication multiplexers, dm0 and dm1, do not 
interrupt. When they do not interrupt, the system will appear to be in 
multi-user mode at the console, however, no getty's are spawned and so 
no one, except the person at the console, can get up on the system. 
If the system is reboot again, the mutiplexers interrupt
and everything is fine and dandy.  However, someone has to be on site
to reboot.  

Below is a copy of /usr/adm/messages showing
what is logged on the console when the mux's do not interrupt and
when the system is reboot and the mux's interrupt.  If you
need/want any more information about this situation, feel free to ask
me.  Do you know what is the problem and/or how to rectify it?


			    Nancy Blachman
     	   	 {allegra!amd!hplabs!sun}!resonex!nancy
			Resonex,  Sunnyvale, CA
			    (408)720 8600



4.2 BSD UNIX #9: Mon Mar 19 15:30:12 PST 1984
real mem  = 8384512
avail mem = 7017472
using 302 buffers containing 838656 bytes of memory
mcr0 at tr0
mba0 at tr4
hp0 at mba0 drive 0
hp0: eagle
hp1 at mba0 drive 1
hp1: eagle
mba1 at tr5
hp2 at mba1 drive 0
hp2: eagle
hp3 at mba1 drive 1
hp3: eagle
uba0 at tr8
zs0 at uba0 csr 172520 vec 224, ipl 15
ts0 at zs0 slave 0
dh0 at uba0 csr 160400 vec 300, ipl 14
dh1 at uba0 csr 160440 vec 400, ipl 14
dm0 at uba0 csr 170400 didn't interrupt
dm1 at uba0 csr 170440 didn't interrupt
aed0 at uba0 csr 164040 vec 170, ipl 15
uba?: stray intr ipl 15 vec 314
uba?: stray intr ipl 15 vec 414

May 25 22:30
4.2 BSD UNIX #9: Mon Mar 19 15:30:12 PST 1984
real mem  = 8384512
avail mem = 7017472
using 302 buffers containing 838656 bytes of memory
mcr0 at tr0
mba0 at tr4
hp0 at mba0 drive 0
hp0: eagle
hp1 at mba0 drive 1
hp1: eagle
mba1 at tr5
hp2 at mba1 drive 0
hp2: eagle
hp3 at mba1 drive 1
hp3: eagle
uba0 at tr8
zs0 at uba0 csr 172520 vec 224, ipl 15
ts0 at zs0 slave 0
dh0 at uba0 csr 160400 vec 310, ipl 15
dh1 at uba0 csr 160440 vec 410, ipl 15
dm0 at uba0 csr 170400 vec 300, ipl 14
dm1 at uba0 csr 170440 vec 400, ipl 14
aed0 at uba0 csr 164040 vec 170, ipl 15