Need help hot air blowing out of drivers side vents
 

Here's the deal. Hot air blows out of the drivers side of my H2 and ice cold out of the passenger side. This only happens occasionally, and right when it does it i here a "pop" noise in the dash. If I turn the ignition off and back on it goes cold, but then usually after a couple minutes "pop" and then hot again. I replaced the drivers side actuator. But as I replaced it when i was messing the little controls that the actuator moves, actually none of those control temperature. So I replaced it anyways since the old one was out, however low and behold, it continues to do the exact same thing. Any suggestions?

Anyone?