This issue should be resolved in future updates to the extensions as they are released. Here is the fix that was found:
Open up your %appdata% folder and browse to Adobe > Dreamweaver CS4 > en_US. Then go to Configuration/Shared/Webassist.
In here you will need to find the WA_Preview.js files for each of the products. When you find the files you will need to update them by doing a find and replace in all the WA_Preview.js files like this:
and replace with:
That will fix the problem.