Can't reproduce this on Singleplayer, neither on Survival or Creative, just on Creative multiplayer so far.
Updated the bug report for more clarify and fitting descriptions.
My greatest apologies for e-mail spams for all of you, I had no idea and my e-mail is pretty full as well ;_;
Still present in 15w40b.
Ville Ollikainen
Can't reproduce this on Singleplayer, neither on Survival or Creative, just on Creative multiplayer so far.