Actual version: 13w07a (wouldn't let me submit with this as the version, so I picked the closest match)

I didn't think anything of it at the time, but the world quit loading for some reason very near my base (once I got there). Anyway, I go in my base to sleep to set my spawn & At first I was having trouble with breaking blocks and my sprinting not appearing to be as fast. It started to rain, so I went to sleep, but when I press "Leave Bed", I can't it won't let me. It doesn't leave me lying in bed, but it doesn't stand me up. I couldn't press Esc to reach the menu to quit the game either. After a friend came and tried to help (he broke the bed & the block I was on/in and it did nothing to release me (though I still fell down to the next block below (I'll get to that in a moment))), I had to hit Ctrl+Alt+Del to manually quit the game (when I logged back in, I was suffocating in the block I should have been standing on; good thing my friend was still there to help). Because this happened before, I hit F11 to release full screen and exited the game via the "X" button.

The layout of my bed allows me to spawn in one of 3 blocks from the head of the bed to past the foot of the bed on the right side (usually next to the head of the bed). I have a secret chest (or had a secret chest) 2 blocks underneath my bed and a way to get up and down using ladders on the side of the blocks below where I have wool covering it. When I first hit "Leave Bed", it seemed to put me on the top of one of the ladders.

Final notes: I did a search for this bug in Minecraft (saw something similar in Pocket Edition, but that's not the same) & found nothing... Also checked for any mention of this in the bug fix list of the latest snapshot releases and saw nothing even mentioning beds.

Oh, and from what I can figure, this appears to be client side & probably rare, but serious.

PS: I don't control which update we run, so suggestions I update will be ignored