power a comparator into a repeater to lock it and you'll see it doesn't work. the start of the problems start to show!
right click on the comparator and it then works. un-power and re-power and all seems good.
log out, reload chucks and it fails to work again.
use a chest (with items in) to power the comparator and nothing useless you use a rs.torch to power it first right click comparator then replace torch with chest and now it works unless you click on comparator again.

only a repeaters and redstone dust can power a comparator on its sides and not a redstone torch or the new redstone block placed by its side.

try them for yourself and see what i mean. the locking repeater powered by a comparator needs to be fixed to either not work at all or work correct as i would very much like to use this feature