please let us know more details. What are your system specs? How much RAM have you got? What is your Windows OS, what is your Mac OS?
This is happening for me in Sonar 8.5.3, Sonar X1B, Pro Tools 9, Ableton Live 8.2.1, and even in the standalone editor.
This is strange. Have you set your audio buffer size to 1,024 samples? Do you have all these DAWs on both PC and Mac? Or what are the exact combinations? Do you get any error message? What are your CPU and memory load when it crashes (see Activity Monitor on Mac, Task Manager on PC)?
Since this is a Sonar thread, are you aware that we recommend the 64-bit version of both Sonar and Melodyne? Please see also the Sonar tips on this page