The Hauppauge Nova-T-USB2 does not build the DVB graph correctly as the output pin doesn't meet the BDA standard for Major & Subtypes.
Thus TVServer gets confused and tries to add a receiver filter.
Unfortunately the Hauppauge filter is also categorized as a receiver also and thus gets a filter lock because it's already in the graph.

h4. Steps to Reproduce
Add Hauppauge Nova-T-USB2 to PC
Start TVServer
Try to use the Nova-T-USB2
Graph does not build correctly.