My Sonar installation is on C: and the VST files and Shared files for Sonar are on F: and have been since the original install of Sonar 8 Producer. Never had an issue with any of the Sonar upgrades so have to question that scook. I've always used the same structure -
Program on C:
Data (songs) on D:
Extras (like Melodyne, Dimension, Guitar Rig, Session Drummer, VSTs) on F:
Runs faster and allows me to have more simultaneous tracks. All the Sonar upgrades have always followed that structure so why would Cakewalk see it differently?