I had the same type of thing happen to me, but I decided it was the off brand receiver, not the radio. To be honest I am all that impressed with the spectrum stuff, especially when a full range with satelite is roughly half the range of my $10 parkflyer knock off.
I had been doing touch and goes all day, probably at least an hour, ran through a few batteries. I was landing in about a 45 degree crosswind (I enjoy crosswind landings.) And I let go of the rudder a bit to let it weathervane a bit, and it just kept turning, and turning, and turning. I was glad I had no power onto the motor, because every control I had was completely dead. My father was sure I was just blaming a glitch, untill as I was walking up to the plane, still no movement. I knocked off the landing gear, but nothing else was damaged. I was actually flairing it, if I hadn't been, I think the plane would have landed itself. Turning the radio on and off several times did nothing. Unpluging and plugging the battery for the plane in instantly gave me servo movement. I did several range tests, even though I knew it wasn't range related. It was maybe 40 ft away when it went awol.
I didn't think to check my battery voltage, but I did a full power pull for 30 seconds, with no noticeable degriation. I figure I still had half my flying to do before I would hit lvc (3.7v's). Where I had my hands off, no motor pull and no servo movement, I don't see how it could have been a brown out. Although I am using the esc bec to power the receiver. So I guess it is possible that the bec overheated.
Other people on this forum brought up that the software on the receiver can hang up, but has a program to watch it, so it will restart on failure. I'm guessing my $10 receiver doesn't have this feature or it didn't work. I had probably close to 50 hours on it without a glitch. For now, I have swapped back to a spectrum brand 6 channel parkflyer. Thi is just my little eflight alpha 450 trainer.