Simpleman.. Is it possible for you to open the "chart tab" (in the main menu system) and take a snapshot of the open menu...??

Insert a SD card in either slot..
Go into the "main menu" system by hitting the "menu" button on the unit twice...
Turn on the "screenshot" under the last tab on the right...
Scroll back to the "chart tab"...
Hit the "Mark" button on the front of the unit...
Remove SD card from unit...
Upload "screenshot" from SD card into this thread...

Maybe a visual reference will help us diagnose your issue...

Rickie