v28 seems to have killed DVD reading in MKIV!

[mstevens]

I downloaded and burned the V28 image, then went to update both MKIV nav systems in our Z4 and X3. Both updated apparently fine. I then loaded nav discs in both. The Z4 worked as usual, both with an original nav DVD and with a backup disc I'd burned myself. However, the X3 will no longer recognize a nav DVD. It just keeps saying either to wait a moment or that there is no nav disc in the drive. I've tried yanking the fuse to reboot the unit as well as downgrading to v27 then back up to the current version, but nothing seems to help. (It's worth noting that it no longer will read the DVD in version 27, either.)

Any ideas what to try next? The dealer is an hour away and I'd love to avoid killing the time that will be required to have them deal with this.