This is definitely an unusual issue and someone from the Tech Support team should be looking into this with you soon. No other users have had any issues like this with the extension, so it may be some other factor.
Have you reviewed the Common Installation Issues document to make sure you've done everything recommended there?
While you wait for a Support individual, you may want to try and rename the Dreamweaver Configuration folder that is mentioned in that document and then reinstall Site Sculptor and start Dreamweaver up again. This sometimes clears up what might be causing your issues.