Exactly as the topic says.
Is there anyway to fix this or should I just save more often?

That's Parents Friend ^^
Ok, just a joke ;) Wow, so much information! Some more details about OS and Hardware could be helpful. Does ist appear at all regions? I always had may crashes at Talanzaar. And what does "too long" mean?

Okay, I'm using a Windows Vista with an AMD 64 Athlon Dual core processor.
I'm still just at the beginning region with the riss farmers, whatever its called again.
I don't know if its related to any of the specific in-game regions.

By playing too long, I mean that it just crashes some time after I load the game. Its simple as that.

http://www.cremo.de/outcast/

It's a german page, but you can see the maps by clicking i.e. on top at

Karte von Shamazaar - Hier klicken!

(before that please click on the left side on "Lösung"

The different regions can be chosen on the bottom of the page.

Anyway, which graphic card are you using, and what is the version/date of the driver?
With other games you are not having similar problems?

Yes, but do you mean within 10 minutes of loading, or a couple of hours? If it's a couple of hours, I wouldn't worry too much.