Your problem is nothing to do with the OS upgrade - it is a faulty/scratched map DVD. Try breathing on it & wiping with a cotton handkerchief. If that fails, pop the DVD into your PC & use Alcohol 120% or UltraISO to burn the DVD image to your HDD, then burn a new DVD+R or DVD+RW from the HDD image using Alcohol 120%.

This may sound peculiar, but your BMW DVD reader is much more sensitive than any PC DVD drive.... I guarantee that your PC will read the disk! I've been playing around with BMW Map DVD's for 15 months.