Well, i've got also a problem with the wifi connection. Wired works like al charm, but wireless is a real problem. I tried all the different suggested settings mentioned in this thread and the other threads, but my laptop (HP Pro-book, Xubuntu) and phone (HTC Desire S, android) are losing the connection, not the wlan connection itself, but I cannot acces the internet after some time, a reboot of the router solves the problem for a random period. While the wired connected computers can acces the internet just fine. Also when I connect my Pro-book wired on the router there is no problem at all.
Strange thing is that when I look into the wireless statuspage of the router (when I cannot acces the internet wireless) there are no wireless clients connected, but my phone and laptop are still connected (wlan status notification on both).
Connecting to my other wireless routers (Asus, Netgear, Linksys) works perfectly.
I think this is my 30th wireless router I configure, including a bunch of myself flashed DD-WRT's, but this is the first time that I cannot solve the problem. I'm running out of options for the first time...
I think (wild guess) the "Power saving by link status" is a part of the problem.