Honda Civic Forum - No heat and I'm stumped

OK, my 2004 Civic LX has me beat. I haven't been getting any heat, and I'm at a loss to explain why.

To start with, about two months ago, the motor that moves the cable that opens and closes the heater control valve went bad. Of course it went bad when it was stuck on hot, so I did have heat then when it was 90-something degrees outside. As part of diagnosing what was wrong, I changed out the heater control switch module in the dash and the heater control valve itself. I disconnected the cable from the heater control valve and move it back and forth manually so that I could have air conditioning. I haven't replaced the heater control motor and I don't know if its related to my problem or not. I also bled the cooling system after I changed out the valve.

With the heater valve wide open (on heat), I get no warm or hot air in the cabin at all, even when the car is warmed up. As part of my troubleshooting, this is what I've done:

I've verified that the thermostat is opening (both radiator hoses are hot)
The fuses related to the climate control system are fine
I verified that the heater control valve is open (although the cable is disconnected.)
I flushed out the heater core. The water came out unobstructed in both directions.
I verified that both heater hoses were hot near where they attach to the heater core at the firewall.
The blower motor varies in speed depending on the switch.
The area behind the glove box is not hot.
I've bled the cooling system twice to make sure there's no trapped air.
The A/C switch works, turning the A/C on and off
The head gasket was changed @40K miles ago. I verified that the head gasket is not leaking.
The vent/defrost switch works fine, changing the direction of the air from vent, to floor, to defrost.

Does anyone have any ideas of what else I can check?

Thanks,

Whit