Tvheadend

Hello. I'm using tvheadend with tbs6985 (4 adapters). I'm using opensource drivers from Luis.
Steps to reproduce problem:
1) Start tv channel on one adapter.
2) Start tv channel on another client on second adapter.
3) In 50% times you will get continuity errors on first adapter during tuning on second.

I've tried to setup dvblink trial and rearranged adapters (starting from all belongs to dvblink then 1 to tvheadend + 3 to dvblink e.t.c.).
And it appeared that there no corruption during watching on dvblink even if I switch channels in tvheadend. There were no corruptions when I was watching in tvheadend and switching channels in dvblink. But there were corruptions with tvheadend when I switch channels on another adapter which was controlled by tvheadend.