recreate the users configuration folder as outlined in step 12 of the Adobe troubleshooting guide:
http://helpx.adobe.com/dreamweaver/kb/troubleshoot-javascript-errors-dreamweaver-cs4.html#main_user_config
after renaming the configuration folder, open Dreamweaver to recreate it, then close DW and open the extension manager.
in the extension manager, uninstall the extensions, then install them again.