If you decide to upgrade to Lion, ProPresenter won’t work right away.

I upgraded and ProPresenter crashed immediately. So I went to the Renewed Vision website and downloaded the latest version (4.2.5). This version would hang on boot up every time I tried to launch it. I had to fix it by deleting the Renewed Vision App Support folder. Lion now has this hidden. Quit ProPresenter. To locate the folder, click on the desktop and press Command-Shift-G. Then type: ~/Library/Application Support/. Then delete the “RenewedVision” folder.

Now it works!