I found this bug where when you point a comparator at a dispenser, and put a torch next to it, it will not dispense. When you do this with a dropper it will.
MC-8248
Redstone torches do not power dispensers in any way, but Do power Droppers
Resolved
Duplicate
0
DicoTheRedstoner
(Unassigned)
Unconfirmed
Snapshot 13w03a
Retrieved
Duplicate of MC-8184, please use the search function to see if your bug has already been submitted. Currently over 49% of tickets are being closed as duplicate.