Can you explain how these channels are not working? Are you getting an error code/message? Or is there a problem with the picture?
It may also help to be specific about which Sky Sports channels aren't working - there's 10 of them and it may help fault diagnosis if we know which ones you have problems with, and whether you're using the SD versions or HD.
As a starter, you've mentioned this problem is only apparent on one of your multiroom boxes - I therefore presume it's not a problem with the other one. Have you tried swapping the 2 boxes around, and checked whether the problem (whatever it is) follows the box or stays with the co-ax connection point?
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