Firstly a direct quote from the NASA website
So the first question is why is our sun an exception to the rule?
There is thankfully some research being done into this at the Binary Research Institute.
The research centers on the changing of the rate of precession of the Equinoxes. Research shows that the rate of change of Precession is different for objects within our solar system as opposed to rate of change observed outside our solar system. Also the wobble is not constant it is being influenced by some outside force.
The other interesting wrinkle in this is that one candidate for a star involved in a multiple system with our own sun put forward is the star Sirius.