RE: Radio Interference
Foosion,
A couple of things to consider.
1. The problem could be caused by interference from servos, however if this was the case it would normally happen all the time. From the way you have described it your problems only happen when other transmitters are operating close by. In general servo cables should be kept as far away from the Rx antenna as possible. If possible avoid running servo wires and the antenna parallel to each other as this maximises pick up.
2. Sensitive receivers are good not bad, but you need it to be SELECTIVE as well, ie to reject signals on other frequencies. Bear in mind however that the problem might not be your receiver, but someone operating a Tx that is off frequency.
One thing you could try is to get a couple of people to operate their Txs close to your model (with your Tx turned on also) to try and localise the problem. You may get some pointers as to which Txs or frequencies cause the problem.
Good luck
Terry