Hi Dmitry, I took your advice and set my Linksys WAG160N to disable 802.11N and now I can set the ESSID. However, while it associates without the freeze and I can scan with iwlist and see all the available neighbourhood Cells... dhclient refuses to give me an address. At least the system doesn't freeze :^) I see the following in the log: root@dug-desktop:~# dmesg|grep wlan [ 34.313404] ADDRCONF(NETDEV_UP): wlan0: link is not ready [ 35.010729] wlan0: authenticate with AP 00:1d:7e:b3:0c:ff [ 35.013086] wlan0: authenticated [ 35.013101] wlan0: associate with AP 00:1d:7e:b3:0c:ff [ 35.017099] wlan0: RX AssocResp from 00:1d:7e:b3:0c:ff (capab=0x421 status=0 aid=1) [ 35.017108] wlan0: associated [ 35.017514] wlan0 (WE) : Wireless Event too big (366) [ 35.025277] ADDRCONF(NETDEV_CHANGE): wlan0: link becomes ready [ 35.025592] wlan0: disassociating by local choice (reason=3) root@dug-desktop:~# iwconfig wlan0 wlan0 IEEE 802.11bgn ESSID:"tsunami" Mode:Managed Frequency:2.462 GHz Access Point: 00:1D:7E:B3:0C:FF Bit Rate=1 Mb/s Tx-Power=27 dBm Retry min limit:7 RTS thr:off Fragment thr=2352 B Encryption key:off Power Management:off Link Quality=107/100 Signal level:-26 dBm Noise level=-95 dBm Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0 Tx excessive retries:0 Invalid misc:0 Missed beacon:0 root@dug-desktop:~# iwlist wlan0 scanning wlan0 Scan completed : Cell 01 - Address: 00:1D:7E:B3:0C:FF ESSID:"" Mode:Master Channel:11 Frequency:2.462 GHz (Channel 11) Quality=93/100 Signal level:-35 dBm Noise level=-95 dBm Encryption key:off IE: Unknown: 2D1A4C1003FFFF000000000000000000000000000000000000000000 Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s; 6 Mb/s 9 Mb/s; 12 Mb/s; 18 Mb/s; 24 Mb/s; 36 Mb/s 48 Mb/s; 54 Mb/s Extra:tsf=0000000053039180 Extra: Last beacon: 28ms ago Cell 02 - Address: 00:17:3F:C8:27:66 ESSID:"WLAN" Mode:Master Channel:6 Frequency:2.437 GHz (Channel 6) Quality=50/100 Signal level:-63 dBm Noise level=-95 dBm Encryption key:on Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s; 22 Mb/s 6 Mb/s; 9 Mb/s; 12 Mb/s; 18 Mb/s; 24 Mb/s 36 Mb/s; 48 Mb/s; 54 Mb/s Extra:tsf=00000034b189e1a0 Extra: Last beacon: 444ms ago Cell 03 - Address: 00:21:55:74:BA:60 ESSID:"" Mode:Master Channel:8 Frequency:2.447 GHz (Channel 8) Quality=73/100 Signal level:-48 dBm Noise level=-95 dBm Encryption key:on Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 6 Mb/s; 9 Mb/s 11 Mb/s; 12 Mb/s; 18 Mb/s; 24 Mb/s; 36 Mb/s 48 Mb/s; 54 Mb/s Extra:tsf=0000000c7548a5a3 Extra: Last beacon: 224ms ago I'm not sure what the IE unknown means. No lease offers are seen: -- root@dug-desktop:~# dhclient wlan0;ifconfig wlan0;iwconfig wlan0 Internet Systems Consortium DHCP Client V3.1.1 Copyright 2004-2008 Internet Systems Consortium. All rights reserved. For info, please visit http://www.isc.org/sw/dhcp/ wmaster0: unknown hardware address type 801 wmaster0: unknown hardware address type 801 Listening on LPF/wlan0/00:18:39:17:d5:6a Sending on LPF/wlan0/00:18:39:17:d5:6a Sending on Socket/fallback DHCPDISCOVER on wlan0 to 255.255.255.255 port 67 interval 4 DHCPDISCOVER on wlan0 to 255.255.255.255 port 67 interval 7 DHCPDISCOVER on wlan0 to 255.255.255.255 port 67 interval 9 DHCPDISCOVER on wlan0 to 255.255.255.255 port 67 interval 16 DHCPDISCOVER on wlan0 to 255.255.255.255 port 67 interval 19 DHCPDISCOVER on wlan0 to 255.255.255.255 port 67 interval 6 No DHCPOFFERS received. No working leases in persistent database - sleeping. Setting a static IP doesn't work either :^( This is using a Linksys WMP300N (Atheros 5416) and Ubuntu 8.10 beta, 2.6.27-5-generic. At least you cured the freezing :^) Cheers, Doug -- The big print giveth and the small print taketh away.