I agree with Jackd - get your thermostat checked. BTW, I also have a duo-valve equipped heating system and I found that as the engine temp reached around 60Deg the interior starts to heat up.
If the thermostat checks out OK it might be worth-while to flish the heater core.
One other point _ when I last worked on the heating system of my car I found that one of the copper end points (the actual valve) broke off the stem and was blocking water flow. It is a fairly tricky assembly procedure if you do not want to break anything...
Ad Jackd stated, thae aux pump only helps in slow going traffic or at low engine speed to ensure an even temp inside the car.
Come to think of it - without the aux pump, what does the plumbing between the radiator hose and the heater core look like ?