Yeah, when PS3 plays files from attached USB disk, it doesn't use DLNA.

Once the video hangs when playing from the PS3 I can still browse via windows 7 to the Tonido (\\ipaddres of tonido plug) and play videos using windows media player, VLC ect.
In this same state the Tonido is not available via the Web browser, however I can SSH to the plug and login.

You are using different services to do so.
Accessing plug using url \\plugip\ will use samba service. To use the dlna service from your windows 7 box, you need a dlna client or look for available media servers in your network.

Also by using SSH and/or web browser you are accessing the plug via ssh service and tonido service, not DLNA.

Thanks, I am aware that the different methods of access use different services. What I was trying to point out is that other services are running, and some services hang until the unit is rebooted.
What is the next course of action I can take to troubleshoot this issue?

It looks like the DLNA library we use has some issue when delivering content to PS3.
Please change log level to trace, and then run as usual and once freeze happens, post the tonido.log file.