Ok, it appears you are loosing all three, sorry very odd, in the city, that could the problem. I am very familiar with loosing remote signal and RTH activates, both times this happened to me it was after a firmware update. Had to send it in for repair.
You really need to try it, in clean air.
Here is my opinion on Firmware updates.
Terrible signal performance
Here is one that might make sense about flying in populated areas.
Lost signal (but not really)
Here is some talking about all the frequencies being transmitted.
Question about Radio, uplink, downlink, frequency, & telemetry
Recently it has came up that the video and telemetry are sent on the same freq, but two different channels.
How I view it, is your loosing signal
#1 to the phantom from the remote.
#2 your loosing video from the phantom to the remote
#3 your loosing telemetry from the phantom to the remote.
All three about the same time, it must me local interference.
Rod
Let us know!