*Possible Workaround* until it's checked.  I too on occasion have had this issue.  This restored "Dave's" functionality for me, and I hope it helps for some of you guys.   After chocks and ground power buttons stop working: * Go to Options page on Dave * Select the Enable button under Help Messages * Select the Disable button under Help Messages * Press Home button and then press Ground Services / Maintenance button * Now check to see if chocks and ground power