Unfortunately (or fortunately I guess, depending on perspective) I cannot confirm your results Euchale. 1.4.1 loads up to a proper modded Banished minecraft instance for me now.
On a different note, when I played Banished before with some friends on a server, we were constantly hounded by enemies at our gate. Any exit from the base was a weak point. This was on 1.3.1 if I remember the version number correctly. We had no shortage of string to start making arcane ingots with. In my single player game on 1.4.x, I barely see enemies any more. An occasional phantom, maybe a zombie wanders in through one of the many open exits, but I've never seen a creeper, skeleton or spider and I've been playing in this world now for about 6 hours. It's my best success outside of multiplayer, six hours in and I haven't died once. Did something happen with the mob spawning? And if I continue to not find spiders, should I just start trading (my incredibly small amount of) dark power for string until I can get the sheep egg quest?
~pre-post edit~ I realize now that I'm playing on normal, and the server config we use is pretty much always set to hard. Maybe that's what's happening to the mob-spawning?