Korps, all the ones where I have seen people having problems with 2.4 "dropping out" have been using 4cell battery packs and I believe that the battery voltage is dropping below the threshold of the reciever and then the reciever resets. This voltage drop only needs to be for a split second and the reciever will reset. I fly with 5 cell or Lipo's and voltage reg and have been flying with 2.4 for over 18 months without a problem. One of my models now has over 150 hrs on it 9mins at a time. All models have a Volt spy in them to keep an eye on the reciever pack, not so much the voltage but the state of charge.

Cheers