There is a 'problem' with the brake master cylinder float. It creates too good a seal causing a pressure difference. This causes the fluid level inside the filter to be lower than the fluid level outside the filter. Since the float is inside the filter, it sets off the brake warning light. Usually this only occurs after the car has been sitting for a few hours and goes away after driving 15min or so.

Replace the filter with the updated filter or modify your filter.

To modify: Cut two small notches 180 degrees from each other. The notches should be as big as the letter U i just typed. Use a pair of side cutters to do the dirty work. Make it look like the new style: