down.card - back.card?

[nightshadow36]

Hi I use the tbs6985 and mumudvb for streaming. UBUNTU
please see below. sometimes I get that in the terminal of mumudvb but the streams still seem to be working.
What does all this mean below? Is it important. Is the card stopping and starting? (If so how to stop it stopping)
Thank you.

Info: Main: Channel "" down.Card 4
Info: Main: Channel "" down.Card 4
Info: Main: Channel "" down.Card 4
Info: Main: Channel "" back.Card 4
Info: Main: Channel "" back.Card 4
Info: Main: Channel "" back.Card 4
Info: Main: Channel "" down.Card 4
Info: Main: Channel "" down.Card 4
Info: Main: Channel "" down.Card 4
Info: Main: Channel "" back.Card 4
Info: Main: Channel "" back.Card 4
Info: Main: Channel "" back.Card 4