Found the problem, in 0.4 there's a loop in pathfinding code that was iterated with an unsigned int, and for some reason your save has a monster with an empty path.
That code was been mostly rewritten for 0.6, but even in 0.5, the bug is no more. -- 1KB // Microsoft corollary to Hanlon's razor: // Never attribute to stupidity what can be // adequately explained by malice. -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org