Need Help with 2.4 GHz conversion !

I have a question that I was hoping someone on this thread might be able to answer. I recently got the Esky Big Lama with the 72 MHz radio system. I purchased a Spektrum AR6000 receiver to use in the Big Lama so that I could control it with my Spektrum DX7 Transmitter which I use for all of my airplanes. I removed the Esky 6 channel receiver and plugged the 3-in-1 controller of the Big Lama into the AR600 receiver. I made sure that two 2 leads coming from the controller went into the proper Throttle & Rudder channels on the AR6000 and also made sure that the two servos went into the correct Elevator & Aileron channels. I performed the binding procedure on it and it powered up perfectly. All of the controls, (ruder, throttle, aileron & elevator), worked perfectly so after about a minute I shut the power off to put the Big Lama body back on. When I started it back up, the light on the 3-in-1 would flash red twice, then just stay a solid red and I could not get a lock on the receiver. I removed the receiver from the Big Lama and tested it on my work bench. I found that the Rudder channel on the receiver, along with the Gear and Aux 1 channels were now not working, however all of the other channels did work. The 3-in-1 on the helicopter would not set itself because the Rudder channel was somehow burned out. I took the receiver apart and there is no obvious sign of damage or burning. Thinking, that it was just a fluke, I repeated the experiment with a second AR6000 receiver and got the exact same results. It worked perfect for a minute then burned out the Rudder channel of the receiver. (Ouch…$100.00 out the window!) I checked the voltage coming from the 3-in-1 and found that the voltage from both the Throttle and Rudder leads were both at exactly 5.0 volts, well within the range of the AR6000. Does anybody know why this happened and have a solution for it. Fortunately, when I hooked the original Esky 6 channel receiver back up to the 3-in-1, it worked perfectly. I know that the newer E-Flight Coaxial Helicopters use a 3-in-1 with the AR6000 receiver with no problems. Is there something in the Esky version 3-in-1 that is just not compatible with the Spektrum receivers? I would appreciate any advice or help in this matter.
Tom