I don't know how you can come to that conclusion when I have has this set up for quite a while and the only thing I have changed is the router... I have had 2 other routers that worked fine in this aspect...except for the dlink. Clearly something in the way they reestablish connection in their DHCP is flaky and non standard.
Routers are not a spare part that will replace any other without a problem. Only some routers are different from the rest, since 90% of all the brands use the same reference design models, only using other/cheaper parts and a different box with label.