With advice like this I'd be jumping brands too.

amazing how folks on other brand radios don;t have problems with 4cell NimH of the AA variety....

Crosby, the set up you refer to is used in a many many planes everyday with very few planes behaving the way your has. However when reports are made of problems the symptoms are similar.

Easy way t test your batteries is too use the servos and other working hardware from the  wreckage that could be salvaged.

Rig up the servos so they actuate a load either via a spring or weights. Simulate loads in the 2kg range for those smallish planes.

If you can get an ammeter onto the servo line you can check the current draw and also a voltmeter/ammeter across the battery to check the voltage and current drop you can isolate a power issue fairly quickly.

The only time I've had a power issue is if the battery was not charged (it happens). If the battery voltage is pulled down by more than 0.5V then theres a problem with either the battery or the loads are too high. 

You mention you simulated the lock out situation in your workshop?  maybe explain around that a little more.

Unfortunately there are members around here who jump to the defense of hardware almost in a knee jerk manner. 

A chum of mine lost his Pilot SBach 30cc recently to a lock out on a certain 9 channel Rx. At least that company acknowledged a potential problem and fixed it...

Hardware failures happen. suggest you isolate it to Tx/Rx to keep this conversation focussed on problem solving rather than it turning into a brand war. If feel happy that you have then take the necessary action that makes you feel comfortable the problem will not reoccur. Don't be swayed by brand loyalists into thinking the problem is with you. Pics of your set up help to keep the conversation focussed because then any issues can be seen almost immediately.