I recommend that you delete your configuration folder and re-install eCar as your Dreamweaver configuration folder might have gotten corrupted.
With Dreamweaver closed, browse to
Volumes:Untitled:Users:jim:Library:Application Support:Adobe:Dreamweaver9
and rename your configuration folder to configuration_old
open the extension manager and remove all the extension you have installed, and then re-install eCart.
Let me know if you are still get the error.