You are right Enjay (Thanks). My \Users\My.Name\AppData\Roaming\Microsoft\Templates\Normal.dotm (word 2010 template)
did not upate, but addig an additional saving step of an overline instead of underline, did it.
Exit the document, come back set it from black overline to black underline and you have black underline into your Normal.dotm
(I tried it after your post enjay - and I have a black underline now!!!)