I have this problem on Ubuntu 14.04. If I try to enter fullscreen while minecraft is maximized, it freezes. If I try to enter fullscreen while minecraft is windowed, it works fine.
It appears as though the block itself was placed correctly, but the texture is placed in the wrong direction.
It appears that it was never "fixed", but no longer occurs; block entities no longer bounce on slime blocks...meaning that this does not happen anymore.