I'm reading this thread because I'me having the same experience today.  Disappointed to see there's no solution or known cause.

I'm also reading this thread because of a reoccuring issue with dissapearing audio transients and wave forms.   As I scroll my drum track, the audio transients disappear then reappear later on in the song.  One section only.   The problem would also occur in Sonar producer 8.5.   A fix should have been in place by now.