I dont have a problem with it, how is yours setup? do you have a standard wired ADSL connection going to a wireless router and then the computers all connect to that? or is it a wireless ISP?
EDIT: If its the first one, go into the router config and try turning off the firewall, that usually helps. If that doesnt fix it then I would say there is an issue with the wireless network cards your using or their drivers. We have 6 computers connected to our wireless router, 2 of them have problems. The interesting thing is that the 2 that have problems are identical cards and models, the others are all different and none of them have problems. The even more interesting thing is that the 2 cards that have problems under windows work perfectly under linux. So anyway, make sure you have the latest drivers installed and see if that helps.