First, You MUST use the AC power adapter when connecting the unit to the computer. But if you are using the AC power and the message still is the same, try the following:
Note:Because each of these steps is a possible solution to the issue, check the status of the device after completeing each step.
!. Restart the computer
2. Close all applications that may be running
3. Temporarily disable any antivirus software you may be running
4. Reset the Nav-U unit by placing a safty pin or something likewise into the reset channel and hold down for approx. 15 sec.
5. Uninstall Microsoft ActiveSync from the Add/ Remove programs and then reinstall it using the Nav-U DVD
6. If possible, test it on another computer.
The troubleshooting steps listed above should resolve your isue. if not, service may be required.The Sony eService Web site at http://eservice.sony.com/
can assist you in obtaining service from a Sony Service Center or locating a Sony authorized dealer.