Yeah, I had "Monsters using Dijkstra" on... Let's see if turning it off help...
EDIT
OK, it helped. Incursion.exe now takes 22 MB instead of 500 and more. And there were no random crashes.
By the way: it seems that a warrior in this game lives exactly until he drinks his last potion of Dimension Door. An enemy with tanglefoot bags or "Grease" spell? You're dead. You're on a pit? You're dead. And encountering any trap is like playing russian roulette: you won't see it, you won't handle it even when you spotted it, so it's basically a matter of saving throws and hit points.
My YASD: I had a warrior who rolled a whip of brilliant energy. Given his very high dexterity, he was a perfect candidate to worship Semirath. So I have found a pantheon, then an altar. I have brought a corpse of a bandit I managed to kill earlier, approached the altar...
...and fallen through a trapdoor. A trapdoor one tile away of that f*****g altar. Straight into a kobold warren, full of gremlins with tanglefoot bags and their traps. OK, I managed to survive - mainly because I had a helmet of telepathy and killed most of the beasts sleeping. So I tried to find a stair up. Then a horde of slow shadows approached me, sucked my speed and, when trying to run, I stepped into a graveyard full of zombies who wouldn't have been a danger if they weren't now much faster than me...