I must say that the issue looks Strange to me.
I have Road Runner Connetion. I already tried at least 10 different Cable/DSL Routers (Brands like: Microsoft, SMC, D-Link, Netgear, Belkin, Speed Stream).
In all cases after I cloned the MAC I never had a problem.
Two days ago I installed a $9.99 Belkin Router from Microcenter, works like a charm.
:sun: