D-Link Air to Belkin

[SP8600]

Hi. I have a D-Link Air wireless card in my desktop running XP and a Belkin wirless card in my laptop also running XP, obviously there on an Ad-Hoc network however the connection is fine for a bit then for no reason it stops and on the desktop it says the connection is not there and I can not connect but on the laptop it still says the connection is there but no packets are sent and I cant do anything.

Also it just connects then does the above over and over without me even touching the computers.

Please some help, I have no idea what this is.