Comment 1 for bug 114310

Confirmed. I have to restart my network too in Feisty (2.6.20-15-generic).
Hardware: Buffalo WLI-U2-KG54 (Ralink rt2570 chipset, using the windows driver with ndiswrapper 1.43)

/etc/network/interfaces
auto lo
iface lo inet loopback
address 127.0.0.1
netmask 255.0.0.0

auto wlan0
iface wlan0 inet dhcp
wpa-driver wext
wpa-ssid xxxxxxxxxxxxxxxxxxxxxxxxx
wpa-ap-scan 1
wpa-proto RSN WPA
wpa-pairwise CCMP TKIP
wpa-group CCMP TKIP
wpa-key-mgmt WPA-PSK
wpa-psk xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx