what's the connection quality first off?
I mean, when I first got my wireless (MA401 for my laptop) I got great speeds...but I was right next to the router. Around the house I usually get 80% or 90%..with a corresponding slowdown.
The reason I mention it is that for a few days a couple of months ago we were getting MAJOR slowdowns like you describe (and disconnects) and I dug and poked around in linux and couldn't figure it out....until I found out my next door neighbor got a brand new 2.4ghz wireless phone! GRRRRR..but at that point, switching channels fixed the problem (now I have to switch channels on the router every 2 weeks or so...the guy seems to love switching channels on his phone).