Sorry that I don't personally have that answer, only want to note that I too am having that problem so any advice would be great. I'm in Spain right now and the streaming dips down to 77kbps, very frustrating. Any advice for either of us would be most welcomed.

As Brandon said, check first the upload speed where the box is located; then check the download speed where you're watching. If the measured upload speed is not ok, it could be useful to replace the router at the box's location - before buying one, just use a friend's router to see if tht is the problem. My slinging speed dropped from 6-700 to 125 (about) and I've changed the router. Now I have steady a steady 700 Kbs wireless and 900 wired, it could be more, but the Internet provider is playing dirty games with me and...; You can have different slinging speeds (wired-wireless, as I do) just because of the "receiving" router. On the other hand, 2000 Kbs seem to me "a little too little" for a LAN slinging - other apparent reason to check the router on the "sending" side. I had 6000 with my old DLink602, now it's almost the same... And last but not least, I sincerely hope that your provider at the "sending" location does not have wicked habits like shaping caping and so on, otherwise said, limiting the upload speed if the data package has over a certain limit...
For the speed check, this is a reliable site:http://www.speedtest.net/
Goog luck!

Slinging from Romania and watching in Canada