Si String Section stops working if starting within a midi clip

Anyone have this issue? If I double clip on the synth (which I added to a project), it's on-screen virtual keyboard comes up and clicking my mouse on those keys makes a sound, as does my Oxygen-61 keyboard or clicking on notes on a midi track's piano roll view. However, if I try to play a midi clip back starting anywhere other than before the midi clip's beginning, the synth goes silent unless I either restart sonar or freeze and unfreeze the synth. 
 
Any idea why I could play a midi clip from start to finish but not starting in the middle without making this soft synth go silent? 

Thanks!
Billy