slow internet behind the router

I am using a D-Link DSL router and in front of the router I get almost 11mb down and almost 1mb up, which is what I am supposed to get. behind the router I get 1 and 0.5.

my setup is DSL MODEM into a gigabit switch then into the routerboard (because I have a piece of hardware that needs to be in front on the switch) I have the stock firewall rules, dhcp server running, and a simple wireless access point.

my dsl router needs NAT on to work, and its firewall off or on does not change the results
I use x.x.1.1 for the modem with a small dhcp range for the single piece of hardware that needs to be in front
the routerboard uses x.x.0.1 and a dhcp range for the pc and such
I use the stock firewall rules
I use a simple wireless AP setup

the connection tested is a gigabit wired nic.

Any help would be appreciated.

CTenney