Posted by BMW_tech on Bimmerfest forum (this guy seems to be on top of these types of issues......

"SI B 34 01 08
CAUSE
When the parking brake is activated with the engine running, the vehicle's service brakes are applied via the Dynamic Stability Control System (DSC). After the ignition is switched off, the DSC signals the EMF to apply the parking brake shoes at the rear wheel brakes. During the ignition cycle, the signal between the DSC and the EMF can be interrupted. If the signal is interrupted, fault code 6032 MECH FORCE is stored in the EMF module, and the parking brake warning is illuminated.

CORRECTION
This situation will be corrected via a software update, available as of March 2008.
(parking brake should only be switched on and/or activated with the engine switched off until available)"

So it looks like it is a known issue and there is a workaround (set parking brake AFTER turning off your engine & before removing the key.) Looks like a real fix (updated software is in the works.)

Hope this helps all of you with this problem.

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2008 4.8i Mineral Green Metallic Sports Package, Technology Package, Cold Weather Package, Rear Climate Package, Premium Package, Premium Sound with iPod adaptor & Sirius Radio, Auto Tailgate, Head up display