EMC, freqmod.o, A-axis, .ini settings, oh my!

Here's the setup:

I've got a stepper-based mill that's got four axes. The A axis is a
rotary table that's bolted to the mill bed so the axis points parallel to
the X-axis.

I'm running the latest rev of the BDI, and the motors are set up to use
freqmod.o.

I'm trying to tune the .ini parameters for the fourth axis so I can
address the rotary table in units of degrees. The linear axes are being
addressed in units of inches.

I've got 200 step/in motors that are being half-stepped. The linear axes
have 20TPI leadscrews, so that winds up being 8000 steps/inch. The rotary
axis has a 1:72 worm gear on it, and uses the same motor as the linear
axes. So at 5 degrees per revolution of the motor, that's 80 steps per
degree.

Now for the troubleshooting:

I've got the linear axes pretty happy. I don't have my .ini file in front
of me, but I use an INPUT_SCALE and OUTPUT_SCALE of 8000.0 0.0,
LINEAR_UNITS of 0.03937007874016 in [TRAJ] and UNITS of 0.03937007874016
inside each [AXIS_*] section (I'm using inches), and a P of 500.0.

I've got ANGULAR_UNITS set to 1.0 in [TRAJ] and UNITS set to 1.0 in
[AXIS_3]. With all the other parameters set the same, if INPUT_SCALE and
OUTPUT_SCALE is set to 8000.0 0.0, the axis works, but it's not being
addressed in terms of degrees. If I change INPUT_SCALE and OUTPUT_SCALE
to 80.0 0.0, the axis ceases to function.

I've tried dinking with this a fair amount. I can marginally get it
working with the SCALEs set to 800.0 0.0, and address it in terms of tens
of degrees (so G0 A9.0 would rotate it 90 degrees), but obviously this
isn't what I'd like it to do.

Has anyone got a stepper system using freqmod.o to work with a rotary
axis? Can anyone share a success story that would help me get this thing
working?

Any and all help is much appreciated.

Thanks,

Tom