I fixed the problem - dumb mistake on my part - I recently added a new DHCP server (created a redundant DHCP setup in Win Serv 2012 R2), but did not set the DNS servers in the DHCP Scope. Once I set those to my required servers, the laptop connecting received the correct DNS servers when establishing a connection to the EA6900.
In this case the EA6900 was functioning as it should as my DHCP server was overiding whatever values were enterred in the EA6900 DNS entry fields - and this is the way I want it setup.
Seems to work well - and getting 800MHz connection with my laptop, with about 20 Mb/sec transfer