I have managed to connect my desktop (kubuntu 9.04, 2.6.28-11-generic kernel with D-Link DWA 110 usb Wi-Fi adapter) to a Acer Timeline 4810G laptop (ubuntu 9.04). All went OK till this morning I installed nfs on both systems.

Now I can see from the laptop the network created on my desktop (via iwlist), but after I try to connect to it (iwconfig wlan0 essid _my_essid_) ping of my desktop returns
Code:
From 192.168.1.1 icmp_seq=6 Destination Host Unreachable
dmesg | grep wlan returns now
Code:
[ 3502.027059] wlan0: Trigger new scan to find an IBSS to join
[ 3504.968034] wlan0: Trigger new scan to find an IBSS to join
[ 3507.872033] wlan0: Trigger new scan to find an IBSS to join
[ 3510.668039] wlan0: Trigger new scan to find an IBSS to join
[ 3511.473337] wlan0: Creating new IBSS network, BSSID f2:96:e6:84:c6:2d
[ 3512.676031] wlan0: no IPv6 routers present
[ 3541.488046] wlan0: No active IBSS STAs - trying to scan for other IBSS networks with same SSID (merge)
[ 3572.312129] wlan0: No active IBSS STAs - trying to scan for other IBSS networks with same SSID (merge)
[ 3603.124035] wlan0: No active IBSS STAs - trying to scan for other IBSS networks with same SSID (merge)
[ 3603.969610] wlan0: Selected IBSS BSSID 8a:9f:71:7a:97:51 based on configured SSID
on the desktop and something similar on the laptop.

There weren't such messages before nfs installation, though I'm not sure that installation caused the problem. What does
Code:
wlan0: no IPv6 routers present
mean?

How do I connect? I don't use network managers, I connect manually, using the following procedure on the desktop and a similar one on the laptop:
Code:
sudo ifconfig wlan0 down
sudo iwconfig wlan0 mode ad-hoc
sudo iwconfig wlan0 channel 1
sudo iwconfig wlan0 key off
sudo ifconfig wlan0 up
sudo ifconfig wlan0 192.168.1.1
sudo iwconfig wlan0 essid '2111'