Adobe today released an update to Dreamweaver CS5, bringing the latest version to 11.0.2. The update addresses small issues with the program since its initial release, and also includes previous updates for Adobe's Browser Lab.
According to some early reports, the update addresses problems with Adobe Dreamweaver CS5 not running properly with FileVault enabled, and people are now able to use Dreamweaver with Filevault enabled.
While Adobe recommends it for all CS5 users, there are some precautions to take before jumping right in and installing it. At the very least, be sure to have a full system backup using Time Machine or a cloning utility (which will allow you to immediately boot, continue working, and clone back if something goes awry).
Some people have reported losing their site definitions after installing the update, so before updating you may wish to export the definitions first. To do this, go to the "Site menu and choose "Manage Sites". Then select the sites from the list (using the Shift or Command keys while clicking to select them), and then click "export". Then choose a location and click "Save", and you should have the sites backed up in case an error occurs.
A few other people have mentioned usernames and passwords being wiped out upon updating, but a system restart seems to do the trick for fixing these issues. If the credential problems persist, open the keychain and remove all adobe-related keychain entries, and then relaunch your Adobe programs and save your passwords again.
For some people the auto-updater is not locating the latest version, so if this happens to you, download the updater from Adobe's downloads site (6.95MB for OS X).