Autopilot droping out of Auto into RTL

Autopilot dropping out of Auto into RTL
Not FS related. Checked FS several times. Believe my setting are not causing it.

The mode change is preceded by this Message:

7/3/2015 8:11:13 AM FE 9 15 33 44 A6 mavlink_radio_t rxerrors 1469 fixed 1010 rssi 82 remrssi 100 txbuf 100 noise 36 remnoise 37 Len 17
7/3/2015 8:11:13 AM FE 9 15 33 44 6D mavlink_radio_status_t rxerrors 1469 fixed 1010 rssi 82 remrssi 100 txbuf 100 noise 36 remnoise 37 Len 17

Then, I sometimes get a message like this after the “mavlink_radio_t rxerrors” message:

7/3/2015 8:11:13 AM FE 33 8C 1 1 FD mavlink_statustext_t severity 1 text Executing nav command ID #16 Len 59

Or Like this.

mavlink_statustext_t severity 1 text Throttle unsuppressed

Sometimes I don’t get a statustext message, but the autopilot drops out of Auto into RTL anyway. I always have a “mavlink_radio_t rxerrors” message before a drop out.

I have improve my antenna, Still have the problem.

Appreciate any idea or help.