Sonar X2 - Waveform Issue/Locking Up

Hey everybody. I've got a problem that I have been trying to fix for the longest time. I'm running Sonar X2 with Windows 7.  I've tried multiple optimization techniques to try and circumvent this problem to no avail. After I record audio, the waveform takes an extremely long time to load (no graphic, "(busy)" displayed in place of clip name), and if I attempt any action in Sonar while the waveform is loading, the program freezes until the waveform finishes rendering. This can be anywhere from 10 to 30 seconds. In many instances, Sonar will lock up or crash frequently once the project file reaches a certain size and a multitude of plugins come into the picture.  This doesn't seem to happen every time I record a clip, and I can see no pattern in these occurrences. The kicker is that this all seemed to start when I upgraded from XP to Windows 7. I never had these problems back when I was running X1 and earlier versions on XP. Any input or advice would be greatly appreciated.