Weird Servo issue?

[Beanie]

OK, so I have a Maverick Atom and it's had a Hitec HS-65 in it for steering for ages, using spek with my DX3.0.

All been working fine, no probs.

I just got a Helios with Spek module and decided last night to bind it to the Helios and begin using that.

Well, once I did this, the servo is buzzing pretty much the whole time, glitchy as hell and getting very hot?

I've changed all sorts on the TX to try to sort it out, the balance, the travel, etc. even when disconnected from the steering then it still buzzes, gets hot and is glitchy.

So the weird bit. If I bind back to the DX3.0 then it behaves impeccably?

Very odd. I'm thinking the servo doesn't seem to get on with me using the Helios???

So I put back in the standard servo, and that works fine with both the DX3.0 and the Helios, no problems?

Anyone got any ideas? I'd like to use the hitec as it's way better than the standard servo.....