I'm running into a similar issue with my Rino 650.
I can send messages and they pop up on the other device, but nothing gets stored in the NOTES section (so I can't see notes which I sent or notes which I received).
The functionality works fine on my friends 650 (messages are stored) as long as the units are close together.
The only difference I found is that they have a 4gb micro sd card installed and I have the ONX Map card installed.
I'm using an ONX Map card, and I think that may be interfering with the functionality.
Maybe Rino stores the messages on the micro sd card instead of in the units memory.