I too am experiencing the issue with black / blank screen since the update. Have reinstalled 3 times including Garmin software and clearing out the links in the registry and still just black / blank screen. I appreciate and look forward to the next RXP update that adresses this issue and I suppose it's back to the GNS 530 for now.
Thank you RXP in your effort to repair and update to fix the issue. Just wanted to say that another user is having this issue is all.