After you have selected a channel in the "Channels" list (left one), subsequent selections cause the "Similar channels on other cards" list (right one) to freeze.

h4. Additional Information
This is similar to mantis TV-927 (also same root cause: BeginUpdate/EndUpdate not paired)

See bug report: http://forum.team-mediaportal.com/mediaportal-1-1-0-rc-3-4-519/only-one-tv-combination-each-time-setup-running-possible-83261