Steering upgrade causes DSC malfunction. Need help!

[sjo328ci]

I recently upgraded my steering rack from the original 15.4:1 ratio to the latest 13.7:1. Ever since then in certain corners (typically freeway cloverleafs and connector ramps) I get a loud growling noise that I can feel in the brake pedal. I thought it was a tire rubbing on a wheelwell at first, but then I tried turning off the DSC and it immediately disappeared. Apparently the change in the steering ratio is causing the DSC to see combinations of (apparent) steer angle and yaw rate that it interprets as requiring brake intervention. The brake application is not smooth at all though. It is a staccato buzz that sounds like a machine gun.

My dealer has talked to BMW about it and the only thing they can suggest is to upgrade the steer angle sensor to the latest P/N. I'm not convinced that this is the solution though because the steering rack upgrade predated the sensor upgrade by several months.

I've run out of ideas on how to solve this problem. Has anyone else done this upgrade and gotten past this issue?