Thanks for your time--and sorry for wasting it.
I got the upload function to work if I took off in F-Mode with Map Pilot running. If I took off with the Go App running, then switched over to Map Pilot (and force closing Go App) and switching to F-Mode from P-GPS mode AFTER takeoff, it didn't work.
Also, I'm no longer getting the SD Read only error--just flew my first mission! Not sure why it's working now, but I'm not complaining!
Thanks again for your time.