Unable to access serial port from non-global solaris zone on netra 240

I am trying to use a serial communications device that is connected to /dev/ttyb on a netra 240 server. This is a solaris zone configuration using solaris 10 0910. I am able to access /dev/ttyb from the global zone but not throught he non-global zone. I have enabled all of the tty devices in my zone named roseanne using

zoneadm -z roseanne
add device
set match=/dev/tty*
end
# zonecfg -z roseanne info 
zonename: roseanne
zonepath: /zones/roseanne
brand: native
autoboot: false
bootargs: 
pool: 
limitpriv: 
scheduling-class: 
ip-type: shared
net:
address: 172.19.160.111/23
physical: bge0
defrouter not specified
device
match: /dev/tty*
dataset:
name: rpool/zones/roseanne/evd_fs

# From the non global zone, I see all of the tty devices except for ttyb

ls -l /dev
crw-rw-rw- 1 root tty 22, 0 Nov 19 17:01 tty
crw-rw-rw- 1 root sys 26, 0 Nov 19 15:55 ttyp0
crw-rw-rw- 1 root sys 26, 1 Nov 19 15:55 ttyp1
crw-rw-rw- 1 root sys 26, 2 Nov 19 15:55 ttyp2
crw-rw-rw- 1 root sys 26, 3 Nov 19 15:55 ttyp3
crw-rw-rw- 1 root sys 26, 4 Nov 19 15:55 ttyp4
crw-rw-rw- 1 root sys 26, 5 Nov 19 15:55 ttyp5
crw-rw-rw- 1 root sys 26, 6 Nov 19 15:55 ttyp6
crw-rw-rw- 1 root sys 26, 7 Nov 19 15:55 ttyp7
crw-rw-rw- 1 root sys 26, 8 Nov 19 15:55 ttyp8
crw-rw-rw- 1 root sys 26, 9 Nov 19 15:55 ttyp9

I have seen several posts describing this problem but I have never seen a solution.
Does anyone have any ideas?