6.5.10 - I think I can answer that:
Myself and a couple of other folks were having an NMEA data going to our autopilots after updating to the previous version 6.5.9. Evidently 6.5.8 or 6.5.9 made a change that messed up the <CR><LF> (carriage return & line feed) at the end of some of the GPS sentences. Walter fixed that for us with 6.5.10 within a couple of days of us identifying the issue with 6.5.9 release. An amazing turn around. I'm pretty sure that was the extent of it (and I'm pleased to say my autopilot works again as a result). No portrait mode yet I'm afraid.