Active symbol stuck on tree prop

[JHEarcht]

VWA 11.1 on Windows XP

I added a small VW standard low-res tree prop (tree 1 sm texture) to a building plan. Next I imported several more tree props into the Resource Browser. I double click or click "apply" to place some of the new props (tree 2, tree 3) but the active symbol doesn't change from tree 1. When I render the drawing in Open GL the correct tree (tree 2) displays in the OIP, but in the drawing "tree 1" is the only tree that will display. For some reason, the active symbol seems to be stuck on tree 1. Any ideas how to get it unstuck? Thanks,

JHE