Hi Denise!
As you suggested, I've updated the software for the MC65. I've upgraded from OEM 01.20.0000 to 01.21.0000, then to 01.21.0103 and then to 01.20.0001. The issue was there in all the versions. Even if the OS comes with .NET Compact Framework, I've also reinstalled the .NET Compact Framework 2.0 SP2 on the device, but to no avail. Nothing has changed.
If you please, tell me what would be the procedure to send one MC65 device to Esri for testing purposes. I am located in Romania. Also, I have to check with my boss if she lets me send the device to you. The device belongs to the company that I work for.
Best regards.