Wow i searched about 2 hours with google and even the bethesda-ppl told me (the only solution i found) to delete all dlc files and start game before steam downloads them again, if i want to play without them. While searching i came to nexus site but didnt see this conversation here, but i felt like and decided that this is going to be my mod-site for Fallout NV. And then i also find this solution for my problem here. What i wanne say with that: is just that i love this site from now on :D And of course a very big thank you to all ppl working on and for nexus....