I was on GPS Chispse 2.42 Beta.
GPS Chipset 2.50 Release Update did load over Express (GUP3107.GCD was after that in the Garmin\RemoteSW - Folder)
But the GPS Update didn't start. So i put back the Original 006B310700_230.GCD (renamed to 006B310700.GCD)
After ejecting form my Desktop the Update to 2.50 start.