The Pando Media booster has gotten increasingly flaky with Crossover over the past couple of months. In a nutshell, it is changing faster than our developers can respond to those changes. GETTING OUR ACT TOGETHER with apps that change on us takes some time - we've got a staff of less than 2 dozen developers who are assigned to cover hundreds of windows applications.
That said, even with all of its immense flakiness, you should be able to get Pando installed, and eventually install PWI. If you're getting errors during the actual install of Media Booster, before it even begins to download the PWI client, the best thing to would be to quit the install, delete the PWI bottle, clear the installer cache as per the directions, here:
http://www.codeweavers.com/support/wiki/mac/mactutorial/installercache
and then attempt a re-install into a fresh bottle. If the download of PWI (via Pando) freezes at any point during the installation process, this can be dealt with by stopping the installation, and then starting a brand new installation in the same bottle, which will allow the Pando booster to pick up where it left off with the download.