Why is it the second post to this question makes me laugh? It is never a possible solution, a question to maybe help resolve the issue, just some sort of humour, I really do look forwards to this question hahahaha.
In all seriousness, it is possible that you have seen far to much already and that your eye sight is so bad the adult channels only appear to be blank.????
Or you line doesn't include the channels of blindness? Ask for a test line in the request thread, I have not found a line which doesn't include them though... not that I ever look at them, dirty filthy channels!