Similar problem running Feisty Fawn.  Retrying with various length names gets different results on different attempts.

02:00.0 Network controller: Broadcom Corporation BCM4306 802.11b/g Wireless LAN Controller (rev 03)
        Subsystem: Linksys Unknown device 0013
        Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR+ FastB2B-
        Status: Cap- 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR-
        Latency: 64
        Interrupt: pin A routed to IRQ 22
        Region 0: Memory at fcfea000 (32-bit, non-prefetchable) [size=8K]

ieee80211softmac       31360  1 bcm43xx
ieee80211              34760  2 bcm43xx,ieee80211softmac
ieee80211_crypt         7040  2 ieee80211_crypt_wep,ieee80211


matt@ubuntu:/etc/network$ iwconfig
lo        no wireless extensions.

eth0      no wireless extensions.

eth1      IEEE 802.11b/g  ESSID:""  Nickname:"Broadcom 4306"
          Mode:Managed  Access Point: Invalid   
          RTS thr:off   Fragment thr:off
          Link Quality=0/100  Signal level=-256 dBm  Noise level=-256 dBm
          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:0  Invalid misc:0   Missed beacon:0

matt@ubuntu:/etc/network$ sudo iwconfig eth1 essid MandS

matt@ubuntu:/etc/network$ iwconfig
lo        no wireless extensions.

eth0      no wireless extensions.

eth1      IEEE 802.11b/g  ESSID:"M"  Nickname:"Broadcom 4306"
          Mode:Managed  Access Point: Invalid   
          RTS thr:off   Fragment thr:off
          Link Quality=0/100  Signal level=-256 dBm  Noise level=-256 dBm
          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:0  Invalid misc:0   Missed beacon:0

matt@ubuntu:/etc/network$ sudo iwconfig eth1 essid "MandS"
matt@ubuntu:/etc/network$ iwconfig
lo        no wireless extensions.

eth0      no wireless extensions.

eth1      IEEE 802.11b/g  ESSID:"MandS"  Nickname:"Broadcom 4306"
          Mode:Managed  Access Point: Invalid   
          RTS thr:off   Fragment thr:off
          Link Quality=0/100  Signal level=-256 dBm  Noise level=-256 dBm
          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:0  Invalid misc:0   Missed beacon:0

matt@ubuntu:/etc/network$ sudo iwconfig eth1 essid MandS
matt@ubuntu:/etc/network$ iwconfig
lo        no wireless extensions.

eth0      no wireless extensions.

eth1      IEEE 802.11b/g  ESSID:"M"  Nickname:"Broadcom 4306"
          Mode:Managed  Access Point: Invalid   
          RTS thr:off   Fragment thr:off
          Link Quality=0/100  Signal level=-256 dBm  Noise level=-256 dBm
          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:0  Invalid misc:0   Missed beacon:0

matt@ubuntu:/etc/network$ sudo iwconfig eth1 essid "MandS
> iwconfig
> "
matt@ubuntu:/etc/network$ iwconfig
lo        no wireless extensions.

eth0      no wireless extensions.

eth1      IEEE 802.11b/g  ESSID:"M"  Nickname:"Broadcom 4306"
          Mode:Managed  Access Point: Invalid   
          RTS thr:off   Fragment thr:off
          Link Quality=0/100  Signal level=-256 dBm  Noise level=-256 dBm
          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:0  Invalid misc:0   Missed beacon:0

matt@ubuntu:/etc/network$ sudo iwconfig eth1 essid MandS
matt@ubuntu:/etc/network$ iwconfig
lo        no wireless extensions.

eth0      no wireless extensions.

eth1      IEEE 802.11b/g  ESSID:"M"  Nickname:"Broadcom 4306"
          Mode:Managed  Access Point: Invalid   
          RTS thr:off   Fragment thr:off
          Link Quality=0/100  Signal level=-256 dBm  Noise level=-256 dBm
          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:0  Invalid misc:0   Missed beacon:0

matt@ubuntu:/etc/network$ sudo iwconfig eth1 essid Ma
matt@ubuntu:/etc/network$ iwconfig
lo        no wireless extensions.

eth0      no wireless extensions.

eth1      IEEE 802.11b/g  ESSID:"Ma"  Nickname:"Broadcom 4306"
          Mode:Managed  Access Point: Invalid   
          RTS thr:off   Fragment thr:off
          Link Quality=0/100  Signal level=-256 dBm  Noise level=-256 dBm
          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:0  Invalid misc:0   Missed beacon:0

matt@ubuntu:/etc/network$ sudo iwconfig eth1 essid Man
matt@ubuntu:/etc/network$ iwconfig
lo        no wireless extensions.

eth0      no wireless extensions.

eth1      IEEE 802.11b/g  ESSID:"M"  Nickname:"Broadcom 4306"
          Mode:Managed  Access Point: Invalid   
          RTS thr:off   Fragment thr:off
          Link Quality=0/100  Signal level=-256 dBm  Noise level=-256 dBm
          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:0  Invalid misc:0   Missed beacon:0

matt@ubuntu:/etc/network$ sudo iwconfig eth1 essid Mand
matt@ubuntu:/etc/network$ iwconfig
lo        no wireless extensions.

eth0      no wireless extensions.

eth1      IEEE 802.11b/g  ESSID:"M"  Nickname:"Broadcom 4306"
          Mode:Managed  Access Point: Invalid   
          RTS thr:off   Fragment thr:off
          Link Quality=0/100  Signal level=-256 dBm  Noise level=-256 dBm
          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:0  Invalid misc:0   Missed beacon:0

matt@ubuntu:/etc/network$ sudo iwconfig eth1 essid Ma
matt@ubuntu:/etc/network$ iwconfig
lo        no wireless extensions.

eth0      no wireless extensions.

eth1      IEEE 802.11b/g  ESSID:"M"  Nickname:"Broadcom 4306"
          Mode:Managed  Access Point: Invalid   
          RTS thr:off   Fragment thr:off
          Link Quality=0/100  Signal level=-256 dBm  Noise level=-256 dBm
          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:0  Invalid misc:0   Missed beacon:0

matt@ubuntu:/etc/network$ sudo iwconfig eth1 essid MandS
matt@ubuntu:/etc/network$ iwconfig
lo        no wireless extensions.

eth0      no wireless extensions.

eth1      IEEE 802.11b/g  ESSID:"MandS"  Nickname:"Broadcom 4306"
          Mode:Managed  Access Point: Invalid   
          RTS thr:off   Fragment thr:off
          Link Quality=0/100  Signal level=-256 dBm  Noise level=-256 dBm
          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:0  Invalid misc:0   Missed beacon:0