Bugged save of vampire in a fey mood trapped in his little home causing severe lag.
errorlog.txt fills with:
path fail: dwarf,Strange Mood,136,96,109 -> 69,117,109: Id #5291:Path Goal Set Mood Building:Station Milling Flood at 136,96,109

Dwarf was a vampire before fey mood occured as it took two or three drained dwarves for me to spot him.

Also: save game has ghost baby of a child that was previously laid to rest in a coffin. Apparently that was not good enough for the little brat and demands an engraved slab.