As Ian suggested I reckon your worries will go if you cleared the dreamweaver workspace..to me that sounds like you had something of webassist displayed when you closed dreamweaver right before you did the new install upgrade. if you delete the dreamweaver configuration folder (providing you don't have third party plugins installed (otherwise you would need to reinstall those as well). But usually if your doing a reinstall of webassist plugins the best way to make sure you won't get any problems is to delete (or rename the configuration folder) then open extension manager delete any webassist plugins there. Open dreamweaver (this reinitislises the configuration folder. Close dreamweaver then install webassist plugins.
Chris