This thread is a good argument on why you should NOT store your plug-ins in system folders such as C:\Program Files.
I never run Sonar as Admin (except to activate it), haven't turned off the UAC on my PC and I very rarely run into these issues because I don't store my plug-ins in system folders such as C:\Program Files.
I instead I store them in a folder created in another location (in my case F:\audio plug-ins).
Easy to backup, easy to restore and easy to organize.

This not only makes sharing your plug-ins between different DAWs much easier it also makes it easy to avoid having duplicate plug-ins show in your Sonar menu listings.
For Sonar 64 bit my scan path includes (just listing the sub folders for brevity):
* 32 bit
* 64 bit
* x64 demos
For Sonar 32 bit my scan path includes (just listing the sub folders for brevity):
* 32 bit
* 32 bit (has 64 bit version)
* Kore incompatible
and for other DAWs I list whatever paths are appropriate.
...Steven