This has occurred to me twice in limited testing, but cannot consistently reproduce.

Bed placed and slept in room inside bottom of mountain [see attached image].

Killed next day by creeper (thankssss!) and respawned 30 blocks or so higher in house on top of mountain , where there is only a chest, no bed. (chest placed after bed, for reference).

"Odd" spawn position is relatively close, could be exact, to bed x-y coordinates, but much higher z elevation.

Later, exited game, started again and my spawn point was similar – up on the mountain near the chest, but this time "outside" near the top of the ladder.
Again, no bed up here.

Have since exited and restarted and spawned correctly near bed. Will attempt to reproduce by dieing again, but have not yet with limited playtime.

World created in 0.3.3, updated this morning to 0.4.0.