Streaming to two different xbmc at same time

I am having an issue I have two xbmc machine and they are connected on a gigabit router which then feeds into another router acting as a switch it is also gigabit

I am having freezes when trying to play a video on each at the same time I thought a gigabit router would be able to handle that kind of bandwidth the videos aren't even 1080p they are simple 350mb xvid and mp4

I have one machine running openelec and the other windows 7 and using smb