I have a Galaxy S3 with 4.3 installed. When using the latest version of the Google Maps app in the navigation/guidance mode all works well until at about the 30 minute mark the app shuts down (goes to sleep?) and I'm back to a blank/black screen. I must then re-select app and destination--all is good again for about another 30 minutes when it again shuts down. Any ideas/help would be appreciated.