Lou, it sounds like you've gone from a DNN 4.x version right to DNN 6.0. Is this correct? If it is did you update the AD provider? There was a major shift on where settings were stored between DNN 4 and DNN 5 which required separate provider versions. If you look under Admin->Extensions you'll see the provider and as long as the version you're running is at minimum the 05.00.02 version you just need to click on the pencil icon beside the provider and you can enter your settings there. If you're using an older version then you'll have to update the provider on your install (I'd suggest uninstalling your DNN 4 version before updating to 05.00.02 or the 05.00.03 RC).

Perhaps a little more informaiton has been learned....  I went to another users computer and they were able to access the site and their user was authenticated right away.   So AD does appear to be working....

Could it hve something to do with me 'logging out' of my own user, then logging in as the Admin?   I just I logged out as Admin and right away it logged me back in as my user via AD.   Then I had to log out so I could log back in as the admin.   When I logged out from admin this time I was not authenticated by AD.    But I bet if I wait a few minutes and navigate back to the portal AD will authenticate me again.

if that is the case then perhaps the key is NOT to log out once authenticated by AD and just give myself super-user rights... that way I will never need to log out.