i've got the video pause problem and kind of a solution.
i've been watching the network graph in task manager on the tversity server. if i start a video it shows the network traffic going out to the ps3, after a short while the video starts. while it's playing the network graph drops off to nothing, a little while later the video pauses.
it seems like tversity has timed out waiting for the ps3 to request more data. then when it does get around to requesting more tversity doesn't want to know. i read somewhere in these forums about the ps3 grabbing the first mb before playing an internet audio stream. if it does the same with video then it may be that tversity isn't waiting long enough for the ps3 to ask for more.
i overcame it by forcing the ps3 to request more data faster. if you start the video on the ps3 and start fast forwarding it starts to ask tversity for more data and tversity responds. if you fast forward a couple of minutes into the video and then flick back to the start (press L1) then the video will play from the start uninterrupted.
this probably also explains the issue with pausing the video. if the ps3 stops asking for data tversity seems to forget about it and loses the connection.
hopefully this is gonna be fixed soon, but i thought this might help anyone struggling to watch thier videos on the ps3.