I have also experienced this. Then, it went away. I have great confidence it will return. I don't complain too much about these things since I am running a 2008 PC with Win 7.
Ever since I subscribed to Office 365 Adobe Photoshop has given me headaches. In fact, I spent 3 hours today with Adobe tech reorganizing my system. They still didn't get it to work. I have a bad feeling Sonar will have new problems.
I find more help on this forum than most tech support from other companies.
Sorry I couldn't help you, but I bet one of the other forum members will.