There is some goofiness with PRV in Sonar X2.
Sometimes it will display completely zoomed out where the notes cannot be seen and sometimes it will display the notes correctly. The one I really like however is that you never know where in the project the PRV is going to open to.
For instance, you are working at measure 45 in your project in TV and open the PRV and PRV opens to some random part of the project even tho now time is set to measure 45 and you double clicked at measure 45.
As far as the notes not displaying correctly in PRV, If you double click on the midi track again PRV will then open correctly - likely as not. At least it does for me... sometimes it has to be done a couple of times.
The quick fix will not address any of the prv issues.