Unbelievable. Really weird.
I once had a similar problem on the first test run of a new bird. It was the metal spark plug cap not fitting together properly, leaving a very thin slit opening. I re-crimped the plug cap back together to close it well, and interference went away.
I think that now, finally, everyone understands that 2.4 gb is NOT immune to interference as initially was bragged....
AV8TOR