ubun2

Hi,
I installed Ubuntu 9.10 Netbook Remix and Xubuntu on my Asus EeePc 1005PE. I like them very much but I got the same problem with both systems: wireless connection keeps on disconnecting. It's stable for a while and then connection gets lost. Signal is good, 58%  then it decreases to 35%, 27% and then 0%. I've never had this problem with windows. Wirless card should be a broadcom and wireless transmitter is at 3-4 meters far from pc, so signal should be excellent.
 
What can I do?
 
Thank you.