Some combination of the uninstall/reinstall cycle must have corrected the error. After I reinstalled DesignExtender and eCart, DataAssist wouldn't work at all (not even the first menu screens would load), so it seems that DataBridge must be the last one installed regardless if using all three components of SuperSuite together. I removed the DB extension, opened DW after the removal to be sure it was gone, closed DW so it would create a new Wincache file without DB installed, restarted the computer, then reinstalled the extension and tested out DA Pages and was able to get a full cycle of pages to generate even if they used menus or validations. Not sure exactly why this particular series of steps worked when the previous attempts didn't, but I'll take the end result in terms of a functional success. :)