Here's what happened:
Me and my brother wanted to play our SP-Games on MP. No Problem so far:
We created a character each and copied our SP-Saves into the MP-Accts-Folder, then renamed them like the *.fl-File of the MP-Account was called before. Worked Fine, but then, my brother bought a Titan, and bribed someone so some Group would like him. It was the first one having an opinion about him, cause the Reputation got reset when using the SP-Games for MP. From that point, any server he went on would crash and the Game if he used the Save in SP. We used a backup from some time before, and again, it worked fine. Then I got myself a Saber, bribed someone, a group of people started to like me, same problem.

We both have got
512 MB DDR-Ram
2100+ Athlon XP
GeForce 4 Ti 4200
He's got an Asus A7N8X,
I've got an Asus A7V8X,
both including AC97 Onboard Sound and onboard LAN

Anyone had the same prob and solved it?

THX