JonD
Make sure to do a VST reset and rescan after uninstalling and before reinstalling. 
 
No offense to Lexicon support, but unless the tech is a Sonar user, its unlikely he would even think of doing this (often crucial) step.

I did and just an FYI, Lexicon has a Sonar expert on staff, according to them.

This is an Update:
I installed the 32BIT and it worked.

I am thinking there is something wrong with their installer or something is missing because the 32bit installer/package is about twice the size of the 64bit. 170MB for 64 and about 230 MB for 32.

Again both are installing into correct directory. 32 into program(x86)
C:\Program Files (x86)\Lexicon\PCM Native Reverb
 
And 64 into:
C:\Program Files\Lexicon\PCM Native Reverb