gobbledegook in iwconfig after NM disconnect

[Richard Neill <rn214 cam ac uk>]

Dear All,

Not sure if this is a bug, but if I disconnect a wireless interface from 
network manager, the result of iwconfig's ESSID becomes gibberish.
I have no idea where the value of

\x90\xEF\xFD\xA5+ dUB5\xAB3q8\xE2\xCF\xDC\x8Db+\xA3\x9F\x1D\xAA1\x82\xA4\xFA\xDCZsl
comes from, or what it means!

Here is an example:

1. While NM is connected to the network

$ iwconfig wlan0
wlan0     IEEE 802.11abg  ESSID:"26PPWG602"
          Mode:Managed  Frequency:2.427 GHz  Access Point:
		00:0C:F6:7E:FA:18
          Bit Rate=54 Mb/s   Tx-Power=15 dBm
          Retry  long limit:7   RTS thr:off   Fragment thr:off
          Power Management:off
          Link Quality=65/70  Signal level=-45 dBm
          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:0  Invalid misc:0   Missed beacon:0


2. Immediately after disconnecting the Wifi, via the NM gui

$ iwconfig wlan0
wlan0     IEEE 802.11abg  ESSID:"\x90\xEF\xFD\xA5+ dUB5\xAB3q8\xE2\xCF
		\xDC\x8Db+\xA3\x9F\x1D\xAA1\x82\xA4\xFA\xDCZsl"
          Mode:Managed  Frequency:2.427 GHz  Access Point:
		Not-Associated
          Tx-Power=15 dBm
          Retry  long limit:7   RTS thr:off   Fragment thr:off
          Power Management:off


3. After running ifconfig wlan0 down

$ iwconfig wlan0

wlan0     IEEE 802.11abg  ESSID:off/any
          Mode:Managed  Frequency:2.427 GHz  Access Point: 		
		Not-Associated
          Tx-Power=15 dBm
          Retry  long limit:7   RTS thr:off   Fragment thr:off
          Power Management:off