This also bugs out for Dropper-to-Dropper updates with the comparator. I was making a counter, and the comparator should have lit up when one dropper is filled up by another. This doesn't happen unless I update a block next to the comparator connected to the receiving dropper. I know my wiring is correct because all I have to do is update a block or replace the comparator and all works as intended. This was the case in both 13w05a and 13w06a in SSP. Thanks.
This is still an issue for me in 13w16b. This not only prevents viewing of a naked horse, it also prevents breeding with these horses I just rode ~10km to get back to my house in SSP. Help would be appreciated.