Currently at work, so I can not ad any screenshots. I'll try to describe the problem.
I am streaming a movie from my router to the HTPC with no problem and (usually, not always) after a while, the transfer speed will drop to zero for 1 second or so. This causes stuttering of course and it usually comes in 'packs' where the problem will be there for a while (usually in roughly 60 second intervals strangely enough). A similar problem will happen when I use VNC. It will be using only a fraction of my bandwith and operating lagfree and then suddenly I lose the complete control for several seconds. With iftop I can see that the connection is there but there is nothing transfered.
Now I am unsure if this is even router-side, or that maybe windows vista or my wireless receiver is to blame. I was just wondering what your ideas were that could cause this, either on the router side, or on the client side.
I've tried playing tos rules in iptables (maximize-throughput, minimize-delay, maximize-reliability). These seem to have no effect, but as far as I understand that is expected behaviour, since they are just in the packet header as instruction for other routers.
To me it appears the connection is dropped shortly and then re-established, especially for VNC.