Programming: MotorRcControl() vs GetRxInput()/SetServo()

[GlennGraham]

Ok, I've been beating my head against this for a couple of days and haven't solved the problem. If I do the following, things work fine:

while(1) {
// control motor connected to #8 with channel #3
MotorRcControl(1, 3, 8, 0);
}

...but the following makes the servos connected to the uController go nuts:

int armASpeed = 0;
while(1) {
// control motor connected to #8 with channel #3
armASpeed = GetRxInput(1, 3);
PrintToScreen("armASpeed: %d", armASpeed);
SetMotor(8, armASpeed);
}

Also, I see a value of 127 returned, no matter the position of the R/C stick.

If I comment out the SetMotor() call I see the value of armASpeed change with the R/C stick position, as I would expect. So, it appears to be related to the SetMotor() call.

I've checked the arguments against the UserAPI.h headers. Do I have a syntax problem? Is it timing? I don't trust this dual processor arrangement (it seems fragile) and I suspect it might be involved.

Thanks,
-Glenn