I have been having a connection problem for quite some time now. At first I thought it was our provider/router/modems fault (Arcor), but we switched providers about 3 weeks ago (Ish) and the problem persists.
Only other thing 2 things I can think of, is either being fixed in 10.5.2, or has to do with our d-lan setup.
Our main computer/modem and router are all upstairs (i live in the basement

). We also have heated floors and the pipes under the floor cause Interference with w-lan, and I do not have a port in my room. When I'm connected via d-lan, I get frequent disconnects, sometimes 2-3 minutes apart, sometimes 2-3 hours. Quite annoying when playing WoW and everyone but you stops moving.
Anyway, when I'm sitting upstairs and using w-lan I have no problems whatsoever, even though my brother is also connected with his PC in his room (also in the basement).
O yes, If I'm downstairs and get disconnected...my brothers PC and the main computer upstairs both get disconnected as well, and we have to unplug the router for a few seconds to get it back up.
:S