Ad-hoc connection disappearing

I create an ad-hoc connection between my Ubuntu 9.10 laptop (wlan0) and my iPod touch, but the connection only lasts for seconds before it is dropped. Why might t开发者_JAVA技巧his be happening?

I use the following to setup my connection:

ifconfig wlan0 down
iwconfig wlan0 mode ad-hoc
iwconfig wlan0 essid Network
iwconfig wlan0 enc off
iwconfig wlan0 channel 6
ifconfig wlan0 up 192.168.0.1 netmask 255.255.255.0

The iPod would connect, and was even able to open Google's page (ip masquerading) in Safari once, but then the connection died.