Note: this is a SERIOUS problem that will break almost all redstone contraptions that contain pulse limiters.
I logged onto my redstone world using the new 1.4.3 Pre release and tested out an anvil dispenser I'd made previously. A bug fix between 1.4.2 and 1.4.3 stopped anvils from vein allowed to fall through a block that had been pulled back by a piston for only one tick, so I added a 4-tick delay repeater behind the piston to slightly extend the pulse. To my surprise, the piston received no power at all. The redstone wire feeding into the repeater behind the piston was powered by my pulse limiter, but the repeater was not drawing power from it. I tested out the repeater on one, two, three, and four ticks, and it only drew power from the redstone wire on one tick.
Steps to recreate:
1) Create a 1-tick pulse limiter
2) Attach redstone wire to the output, and/or a repeater on one tick of delay
3) Feed it into the input of repeaters on one, two, three, and four ticks
4) notice that only the repeater on one tick becomes powered.