I figured I was overlooking something. In any event, thank you both for clearing up the issues and thanks for the script reference. This is the best modeling software!

In Preferences > General, at the bottom, there is a checkbox to "warn of style changes when creating scenes". If that is checked, a dialog should pop up every time you change the style to create new scene without affecting existing scenes. I have checked this box and the warning does not appear. Instead, a new scene is created and the dimension layer that is new to the scene is applied to existing scenes that have different dimension layers. I have to go back into the existing scenes, turn off the new dimension layer and update each scene. I removed sketchup and reinstalled with no luck. I am using sketchup v8, free version, on XP. Any thoughts? Much appreciated.... Keith