Just about every channel in that folder has TV Catch Up you will see the small time clock in the corner. I tested 2 MAC's for the same server 1 with STB... APP the other with iSTB. I found something very odd with TV Catch Up with both apps. When I go to TV Catch Up to select the date and time for the episode to watch it would open for the correct date and time but was 2 channels off. Example if I were on the Travel Channel then went to TV Catch Up. Say today is Saturday and I select Friday and I select the show that starts at 1PM. It ends up opening the show for that date and time but its the Destination America channel which is 2 channels before Travel Channel. So I went 2 channels after Travel Channel which is HLN HD I open it go to TV Catch Up and select Friday 1PM show and it opens the Travel Channel and it plays the Friday 1PM show. This happened with both MAC's on both APPs.
Not sure if this helps in anyway or makes it even more confusing but I hope you are able to solve the problem.