Glenn,
Is "preview", perhaps, disabled on your Dreamweaver? I have had no problems with the preview so far.
To check, (keep in mind, I am on Mac so I am not sure how different this will be on Windows), you need to to go to EDIT > WebAssist Preferences... then in the dialogue box, click the preview and in there is a check box that when checked will disable the preview.
Best regards,
Brian