Today we released MediaTomb version 0.7.1, solving the DSM-320 lockup issue. Please test it and report if there are any further problems.
The fix was achieved by adding mimetype to upnp:class mappings (see documentatoin and take a look at the config.xml for more details).
Further, we decided to provide RPMs for the UPnP SDK (their project page is at http://upnp.sf.net ). The reason for this is quite simple: it is not so easy to set up from the tar.gz because it does not use the default configure system, and it requires special options before compiling. Those are needed to ensure optimal performance of the internal webserver when multiple requests are coming in.
For now we will focus on the next feature: sorting media and virtual containers.