I purchased and installed Z3ta +2, and can run it in stand-alone mode. However, even though it's installed in a VST Plugin folder, and the folder is listed in the X2's preferences, and I've rescanned it a hundred times, and I've moved Z3ta to its own folder and specified that folder explicitly in X2's preferences, Sonar X2 will not display Z3ta +2 as a synth.
 
What have I not done?
 
- John

It may be that Sonar does not have the required permissions to access it in its current location. Did you run the installers for both programs as a "run as administrator" option? Are you running Sonar "as administrator?"

By any chance did you install X2 as 32 bit and install 64 bit version of Z3ta?