Sonar Track automation: fader pops back to original position when I let it go...?

I'm learning about Sonar Platinum's Automation...
I notice that if both Automation Read Enable and Automation Write Enable are selected for a track, then...
     ...if I use the fader to automate the track's volume, then when I let go of the fader, the volume pops back to whatever level it was at before I started recording the automation.    Annoying, or at least not what I would expect.
    However ...if ONLY "Automation Write Enable" is selected (Automation Read Enable is NOT selected), then during automation, when I let go of the fader, the level remains where I last put it. Instead of popping back arbitrarily to its earlier level. That seems correct.
 
Is it SUPPOSED to work that way? I mean, is it supposed to be the case that if I have both READ and WRITE enabled, then during fader-riding the level automatically pops back to its previous value when I let go of the fader?