Overtone sin-osc ignoring mult and add?

Question

Overtone seems to be ignoring the mult and add arguments to sin-osc. Wanted to make sure I'm not missing something silly before filing a bug report.
This snippet should vary the amplitude from 0.6 to 1.0:

(definst sin-test [freq 440]
    (* (sin-osc:kr 0.5 0 0.2 0.8)
       (sin-osc:ar freq)))

Instead its clearly multiplying by -1 to 1 (going totally silent in the middle). Setting the mult on the sin-osc:ar in this snippet also has no effect. The equivalent in straight supercollider behaves as expected:

{ SinOsc.kr(0.5,0,0.2,0.8) * SinOsc.ar(440)  }.play;

I notice that the the tremolo example on the overtone getting started page does the mult and add manually, but figured they were just being explanatory:

(definst trem [freq 440 depth 10 rate 6 length 3]
    (* 0.3
       (line:kr 0 1 length FREE)
       (saw (+ freq (* depth (sin-osc:kr rate))))))