When trying BrotherhoodI had the same problemthat I had with Assassins Creed 2in this thread http://tinyurl.com/3wu2kcv and the solution to that was the same, disabling GLSL.
And I have noticed that thats issue wasn't just that the shadows were wronly placedbut also that the shadows oft stationary things like buldings for example, moved when I moved the camera and not just when the sun moved as they should.
But that was, as said, solved by disabling GLSL.
And the problem that remains is that a rather large square of (by what I can tell) is som kind of shadow, with the character in the center, goes wherever the character goes. And it also seems that this "shadow" and some of the other ones, consist of dots. And not as a smooth dark surface.
I hope someone have an idea what the problem is and hopefully a solution to it :)