Audio Dropout in Sonar Platinum

In short, increase ASIO buffer size.
Long: http://www.azslow.com/index.php?topic=395.0
 

What Driver Mode and audio interface are you using?  What are the sample rate, bit-depth, and (if using ASIO), what is the ASIO Buffer Size set to?
 
If are recording and your project has plugins that use Look-Ahead processing (convoluted reverb effects), that can cause audio issues.  If so - try swapping those out for some other less resource intensive reverb until you finish tracking, and when you move on to mixing, you can swap the convoluted reverb plugins back in - just also make sure you really jack up the ASIO Buffer Size, so it has enough room to do its processing.  
 
You can quickly test your project to see if it IS one or more of the plugins giving you grief - hit the 'E' key on your computer keyboard, and that will toggle off/on the bypassing of all effects.  If your issues go away when you do that, then for sure plugin(s) are at least part of, if not all of, the root cause.  (Hit 'E' again to turn effects processing back on).
 
Bob Bone