VintaSoft Imaging .NET SDK and Plug-ins Discussions

I am working with the example app ImageViewerDemo in VS2010/CSharp and am running into an issue with the thumbnail viewer control. After following the steps below I see a red bordered box reading "Parameter is not valid" in the viewer on the right side (but the thumbnails continue to display correctly).

Open multipage tiff.
Select page 1 in thumbnail viewer.
Rotate page 1 (either direction, doesn't matter but I'm doing 90 degrees clockwise)
Select page 2 in the thumbnail viewer.
Select page 1 in the thumbnail viewer.

I've made no changes to the demo application code included with the version 4.0 evaluation installation. I'm running Win XP SP3. I used to have the V2.0 imaging sdk installed but I have uninstalled that (removed from the GAC) and installed the 4.0 evalutation version. The 2.0 version did not seem to have this issue. The application that I want to upgrade to the 4.0 control makes heavy use of the thumbnail viewer and image viewer and various rotate/image manipulation functions.