Changes made from version 3.90 to 4.00:
Added support for acceleration greater than 4g
Added support for mobile app improvements
Fixed issue with losing GPX logs when taking a photo while recording video
Fixed issue with missing accelerometer calibrations causing bad acceleration data to be recorded
Fixed some translations
Fixed several issues that could cause the camera to crash
http://www8.garmin.com/support/download_details.jsp?id=6565