For the benefit of others, I wanted to post the steps that fixed this issue for gbrozk1:
Open Extension Manager CS5.
Select Dreamweaver on the left, and then remove the HTML5Pack (11.0.3 Updater) extension.
Repair the installation of Dreamweaver using your original installation media.
To do this, insert your original installation DVD, or double-click the downloaded DMG file, and then double-click Set-Up.app to begin the installation.
When given choices of which products to Install/Re-install, uncheck everything except Dreamweaver. (That is, we need to be sure Dreamweaver is selected to be re-installed. Re-installing repairs the installation.)
Follow the remaining on-screen instructions to complete the re-install/repair of Dreamweaver.