hi Gordon,
when updating to NT12 it's recommended to "reset" the default CSS settings, and the default button settings, as these defaults do change from time to time. (In fact, for CSS, I recommend leaving the "reset" checkbox on, unless you need to override something.)
WebServer Procedure, NetTalk Extension,
-- Styles, "Reset to Defaults" (Repeat on each Tab)
-- Buttons, "Delete" the buttons. (As you delete them, they get added to the bottom of the list, so when the UploadButton comes around again then you've done all of them.)
Cheers
Bruce