Gyro lock failure.

[MeRodent]

Currently I have a Twister storm 3d with the standard HL400 gyro which I'm in the process of converting to Hitec Optic 6 with FrSky telemetry module.

If I connect the original Twister r/c and module the gyro led will light after a few seconds indicating that it has set the direction.
When I use the Hitec/Frsky combo the gyro will not set and no rudder control is exerted.

If I disconnect the gyro gain from the reciever the gyro will set and I can control the rudder but the gyro will not control the rudder.

Am I doing something obviously wrong?
Is the HL400 just a crap gyro?
Is it likely that the gain is not being sent (transmitter problem) and stopping the gyro from setting (gyro gain is set to 50% on the controller)?

Should I just give up and run around with the helicopter saying "vrooommmm vroom.."?