SCCM Supersedence problem

We have an application deployed through Software Center - ver 22 - which must be updated to v24.  I want to uninstall v22 wherever, and only where it's installed and replace it with the new version.  

My test OU I have two machines.  One had v22 installed and one did not have the application.  

I built a new Application for v24 and configured Supersedence on v22 with Uninstall.  I set the Deployment Type/Install Behavior/Requirements for membership in my test OU - my two test machines only.

After Deployment:
Machine #1- v22 was replaced by v24

Machine #2 - v24 was added to Apps & Features

I need the deployment to skip installing v24 on any machine which does not already have v22 installed. 

Can someone tell me what I missed?

Thanks!

—A