you can either cut and paste the repository to the new 1.041 directory or create a new checkout and delete the old one, the cut and paste works fine as long as all files copy completely, then right click on the folder and in the tortoise menu do a 'cleanup' command. this method saves you from re downloading all of the textures and meshes

Running Windows 7 64bit btw

GTX 295 + Core I7920 + 6gb of Ram

Huh?

I had a problem and I had to reinstall sins, and since I have the Digital version I can't choose what version of entrenchment to install so it installed 1.5 for me (Hooray..) Is there any easy way to revert to 1.041?

It seems to work fine with 1.05 - shouldn't be a problem.