Yesterday, Adobe released the Dreamweaver CS5 11.0.2 Updater. The updater fixes a few critical bugs that were discovered after the shipping of CS5, including application launch failure on some Macintosh machines, and crashing when choosing to undo operations with Live View turned on. In addition, the updater includes the Browser Lab/Dreamweaver integration work for CMS support that went into 11.0.1.
Some Macintosh users have reported site definition usernames and passwords disappearing after updating. You can resolve this issue by restarting your computer.
Other users have reported losing their site definitions after installing the update, so be sure to export your site definitions before running the updater. (Site > Manage Sites > select a site/sites, click Export, and save the definitions to a location on your hard drive.)