It sounds like it could be a problem with your dreamweaver installation. Do you have eCart or site import? It sounds like dreamweaver floating windows might not work properly and both of those products use floating windows, which is why I ask. If they also didn't work similarly it would support my guess.
What version of Dreamweaver are you using? Did you install from adobe downloads or did you install from a disk or other location? It might require a reinstallation of Dreamweaver to fix if I am correct.