It seems that you are having some issues with your Slingbox PRO-HD since the audio signal drags.
Most of the times, this issue might be related to a pending audio drivers update. With this in mind, I recommend you to check the following thread and follow the included recommendations:
Hope this helps!
Thanks for the heads up. The computer drivers all all up to date etc. A very interesting issue, is it seems to be dragging only on one off air channel. This channel is running SD channels only. The other broadcasters are in HD. But that should not matter - my other receivers are not having this issue.