I've posted a new public beta (build 909) for registered users, This build offers an option to adjust the upload packet size.
XBOX users have reported an increase in performance when changing the packet size to 2048.
I would recommend adjusting the packet size and see what size works best for your internet connection. Try 2048 first.
For details regarding build 909 please visit this thread
http://forum.flashfxp.com/showthread...=&postid=12220