PWM channel A and B behaviors? (voltages)

I'd never used the PWM before, so just for fun I tried hooking up two LEDs: one to digital out 0, and the other to digital out 1.  Then I ran the following code, expecting both LEDs to be driven the same (about 50% duty, then about 100%)  The documentation implies that channel A and B are driven the same by default?

{

    PwmOut_SetActive( 0, 1 );

    PwmOut_SetDuty( 0, 500 );

    Sleep( 2000 );

    PwmOut_SetDuty( 0, 1000 );

    Sleep( 2000 );

    // turn the PWM outputs off

    PwmOut_SetActive( 0, 0 );

Instead LED on Channel A (digital out 0) lights up and gets brighter as expected, and the LED on channel B (digital out 1) does nothing.  I disconnected the LEDs and using my multimeter I saw that digital out 0/channel A generates about 2.4v then 4v, but digital out 1/channel B generates ~.3v and then ~.5v which is no where near 2.4 and 4v.

It looks like either a) there's a trick to getting channels A and B to behave the same, b) they don't and I misunderstood the documentation, or c) something is wrong with my board.  Any ideas?

I'm using controller v1.0 (one of the very first!) with mcbuilder 0.6.0

Thanks,

Dave