xfi gateway "not internet compatible"

So i recieved a new xfi gateway.  Plugged it in, ran thru the activation, couldn't get my IPv4 IP ( to set up an allowed connection ).  Logged into the router, saw that there was an IPv4 config but no IP was being set. Called support and was told the new gateway wasn't "internet compatable".  So I went back to the old gateway and recieved a v4 and a v6 address.  So the question is are the new gateways really not IPv4 compatible?  I did like the increase in speed the new gateway provided.