Enable PWM on 3.8.13-bone59 (Error: Period value conflicts with channel 1)

Hi

I'm trying to enable pwms using the pwm_test driver but I'm getting an
error when changing the period.

(from dmesg)
Period value conflicts with channel 1

I ran the following commands

modprobe pwm_test
echo am33xx_pwm >> /sys/devices/bone_capemgr.9/slots

echo bone_pwm_P8_13 > /sys/devices/bone_capemgr.9/slots
echo 1000000 > /sys/devices/ocp.3/pwm_test_P8_13.15/period

echo bone_pwm_P8_19 > /sys/devices/bone_capemgr.9/slots
echo 1000000 > /sys/devices/ocp.3/pwm_test_P8_19.16/period
(this one gets the error)

I seem to remember that this was a problem last time I tried using
pwms (about a year ago)

Has anyone found a solution?

Thanks
/Jacob