I've had a good look through all the literature for support on the Sony range and it seems very limited in what it can play over DLNA. Even though the file may playback fine from a usb stick it seems that Sony have chosen to not support these formats over DLNA.
The only thing that is now making me think again is the fact that most of these posts were from some time ago (in some cases a couple of years) and it may very well be a config issue that can be solved in our dynamic media engine.
Can you do me a massive favour and mail me some logs? I need to get the client signature from the logs so that I can build you a dedicated profile and that will also allow us to communicate more effectively via email.
Could you do the following:
1) Edit the config file http://forum.tvmobili.com/viewtopic.php?f=8&t=143
and make sure the AuditLevel setting is set to 5.
2) From your TV, browse to an empty video folder that you know contains mp4/mkv files.
3) Send the log files to me (support @ tvmobili . com). To locate log files use the following post http://forum.tvmobili.com/viewtopic.php?f=8&t=149
It may take a few tests but we might be able to get you up and running