Are the two normal actuators for the driver's side, and the third different one for the passenger side? The image seems to be missing from the forum post you linked to.

I have a 2003 SLE that does not have dual climate control. Of course since it's now summer it's decided to give me problems. The driver's side blows much harder than the passenger side but hot. But it will eventually start getting cooler when I've been driving at highway speeds for a while (however ...