I have no experience with EagleTree systems, but It sounds like Nyquist limit problem.
http://en.wikipedia.org/wiki/Nyquist_frequency
> HB L2PE + MMM + Medusa 60-1600 @ 6S A123
> HB LSP + MMM + Medusa 70-1600 @ 6S2P A123
> AE B44 + MM + Medusa 50-3300 @ 4S A123
> AE J82 + SW 5700 @ 2S LiPo
> AE TC5R + MM 6900 @ 2S LiPo