Since installing Dreamweaver 8, expanding the files panel to show both remote and local sites caused freezes. The application would become unresponsive, and a few seconds later "not responding" would show up by Dreamweaver's title in the force quit window.

Updating the application did not help. However a suggestion in the Emerging Issues document did provide a work-around: Create a new, empty site. Select that site in the un-expanded files panel. Right click the Files tab and select "Group Files With>New Panel Group".
Once the Files panel is moved to a new group by itself, expand the panel. Then switch back to the site you were working on.