adjustments made via a plug-in not visible in viewer

This just started happening, and I'm not sure the cause, if you have any ideas I would appreciate hearing them.

If I make an adjustment with a plug-in (for example Nik CEP), after making the adjustments in the plug-in and saving the changes, i'm returned to the viewer but the adjustments aren't renedered into the viewer image.

If I change the view from the Viewer to the Browser or even the Split Viewer, I can see the changes made via the plug-in.

Oddly enough, if I choose to Crop the image (by pressing the C button), the crop tool and small context window come up, and the image immediately changes so I can see the changes made by the plug-in.

If I simply close the Crop tool without cropping (by x-ing out the small context window), the image reverts and the changes made in the plug-in are again not visible.

I've tried repairing the permissions and the database.

I didn't think this would help because I have a few different libraries, and this same behaviour occurs within each.

I've created a new library and was able to reproduce this (mis)behaviour.

Just to be thorough I also removed the preferences and presets.

I also reinstalled, but this didn't help either.

I'm on Lion, but have the CD; Apple's posted instructions didn't quite cover this scenario.

The only thing that seemed out of the ordinary with the reinstall was that when I issued the following command (from Terminal):

sudo pkgutil --forget com.apple.pkg.Aperture

I received a message back that said something like com.apple not found in /

Any ideas what causing this problem and how it can be corrected?