Server crashes unless a player near spawn joins first

The server crashes with either seg fault, or bus error when a player far from spawn is the first to join after a server restart. If I join a player at spawn first, it seems fine. This is reproducible every time the server is restarted.

Vanilla server. No bukkit or other modifications. Appears to affect 1.5.0 release, 13w11a snapshot, and the 1.5.1 prerelease.