When working away from base, I use Sonar VS (32-bit only) on a 64-bit laptop with the VS-100 hardware. I am about to upgrade from Dimension Pro LE, that was bundled with Sonar VS, to Dimension Pro.
My question is:  Do I install the 64-bit version of Dimension Pro, since I have a 64-bit machine, or do I have to install the 32-bit version, in order to instantiate the Dimension Pro VSTi  in Sonar VS which is 32-bit only?
In other words: Can you instatiate a 64-bit VSTi in a 32-bit VST host that is running on a 64-bit machine. I’m really confused!
Many thanks
Alan T

Use the 32bit version of the instrument.

I had the same dilemma. I installed the 64-bit version, and it works fine. I recall that installing it was tricky because it defaulted to the 32-bit program files folder. Also I was confused about DXi vs. VST versions. I believe that the 64-bit version is VST only. I had to call Cakewalk for help. 

For this kind of money, it's reasonable to expect to be able to install the 64-bit version of Dimension Pro (if you're using Sonar 64-bit).