after a lot of trial and error to get a screenshot of the hotbar glitch i have captured a picture of it happening. the first pic (screenshot 1)shows how the hotbar should look with the half slabs in it. the second pic (screenshot 2)shows what happens during the glitch. this change happens very rapidly and occurs in bursts of 5-7 seconds. it happens randomly.
pictures of the graphical glitch of the half slabs when placed, unfortunately, since the graphical glitch with the half slabs in the hotbar is only a flash, i was unable to get a screenshot of it.
yeah, im currently on the 1.4 pre-release as well. it happens to me whether or not there are alot of entities around though, its nothing game-breaking, but its a bit of a distraction and annoyance.