sounds like the users configuration may have become corrupted.
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 the configuration folder has been renamed, open DW to recreate it, then close DW.
Open the extension manger, and uninstall all extensions, then reinstall them.