-When you place a slab, then a block over it, it becomes impossible to place a slab between them. (Screenshot 1) - Same is true of redstone comparators and repeaters, possibly others. It's impossible to change the setting on these things without removing the block above it first. (Screenshot 2) -Changing worlds puts you into global chat without a message or anything -Falling a large distance ~50 blocks onto a slab sometimes deletes your items, this occurred a lot yesterday (No screenshots, but Random0ne and NMB can confirm)
What client version are you running? The default channel you are in is remembered per world. If you change your default channel in that world, it should remember per world. I change worlds all the time and don't find myself in global chat. Oh boy, that's a bug in ezeiger92 's recent mob dropper nerf code.
I can confirm this happens to me as well. I am running 1.7.10. However it only happens on creative and survival, not vanilla.
PieSquared761 Jojomojobfh Appears to be out of data NoCheatPlus, updating survival and creative. -------- Both updated, problem seems fixed for Jojo. (block placing, not the channel switch) Try it when you get a chance, Pie.