I'm also interested to get the Linsn receiver card(s) working.
We use them here in professional led advertisement boards (e.g. 25 sqm, or bigger), they work quite good IF used with the sender card. Working without would be awesome. Although it can be used directly with the Linsn configuration and sending software, but this is extremly buggy and erroneous.
I'm also that guy, that you probably found at the german board (including the capture): http://www.mikrocontroller.net/topic/352894
In the past i tried to get it somehow working and somehow succeded, in a very limited way that I can control some pixels, but the protocol as you already noticed understands different formats (or so).
I have also contacted Linsn directly regarding informations, but I got only interesting data for the USB serial connection to a sender card, which is in this case not that interesting (the sender to receiver card work in another way, they did not use normal ethernet framing, only the PHY for physical making 8b10b and so on are used).
If testing should be done or something else, like further investigating on the protocol (I'm also interested in the dimm/brightness function, which seems to be in the header of the first packet), then I can maybe help.