MySQL Forums :: Triggers :: Server crashes

I created the following trigger:
CREATE TRIGGER update_pos BEFORE UPDATE ON pos FOR EACH ROW
BEGIN
IF NEW.quantity <> OLD.quantity
THEN
SET NEW.modified = 1;
END IF;
END
Each time I make a simple update on table pos mysql-nt crashes (restart of service neccessary). However when I modify the trigger to
CREATE TRIGGER update_pos BEFORE UPDATE ON pos FOR EACH ROW
BEGIN
SET NEW.modified = 1;
END
it works without any problems. I tried 5.0.3 and 5.0.4.

Dennis