Hi, I have also the VIM2 and the DTV expansion board.
I have the same problem reported by rudi.
Although I'm seeing all my adapters in thveadend tv adapters, I can't open any channel (and all the muxes fail). I guess it seems to be a problem of the dtb driver developed by kszaq.
If instead of using this dtv board in vim2, I use a external sat-iptv, everything works as expected in tvheadend.
Regards.