NealClark
Some plugins don't appear to work correctly unless it is run "as Administrator" when creating and editing a project. So I have found that I have to run it "as Administrator" all the time to save all the messing about.
Old plug-ins sometimes want to access parts of the registry or drive that need elevated privileges. This is because OS security has changed after the plug-ins were written. The one example that was included with SONAR for years is Pentagon. While there is a 64bit version, it still uses part of the registry that was changed for Vista requiring administrator access. The fix in that case is modify the registry
http://forum.cakewalk.com/FindPost/3319219 It may be possible to figure out what other plug-ins need using
Sysinternals procmon. For example, here is what Pentagon looks like in procmon when it does not have rights to the registry (NOTE: the filter settings).

Access is denied for
HKLM\SOFTWARE\rgc:audio Software\Dxi\Pentagon I