Jumping and placing Redstone repeater will cause repeater to disapear and be lost forever.

Cannot reproduce in 13w11a, neither with repeaters nor with comparators.

Can reproduce but not with jumping. To me this happens from time to time when I am too close to the block I am trying to put repeater in. How to reproduce:
1. Build a 3x2x2 wall of any material you like.
2. Extract a block in a center of this wall on your head level to form a niche.
3. Try placing a repeater in the niche while holding walk key against this niche or just standing too close to it.

This seems direction dependant. I can only experience this putting a repeater in east or west direction.

Isn't that a duplicate of MC-8471 ?

You mean like this ? Can still not reproduce (13w11a)
Did try in CSP.

Yep, probably it's the same bug as [MC-8471|MC-8471] describes. Its funny that I also couldn't recreate this today for a second time until I've done what reporter suggests - jumped in 2 meters high space trying to place repeaters under my feet.

Now I've opened some doors, killed some zombies and shot myself a couple of times and I can't reproduce again. Such a wonderful heisenbug I'd say.