What extensions including the version numbers are installed?
the extensions that we offer that are compatible with DW CC are:
eCart 5.0.7
Free Tools 1.0.5
Design Extender 1.1.5
Data Bridge 1.1.4
and should be installed in the order listed above. You can try uninstalling Data Bridge and Reinstalling it, and also resetting the workspace layout:
go to Window -> Work Space layout -> Reset '<your layout name>'
and Delete the Dreamweaver Cache file from the users configuration folder:
http://www.webassist.com/tutorials/Common-installation-issues