Okay, I did some more searching on the web and found a solution. As it turns out I was looking in the wrong place, the actuator on the front axle passenger side was the culprit. GM, in an act of stupidity, used a thermal activated actuator which, surprise surprise, is trouble prone- slow to engage especially in the cold, or not working at all. There is a TSB (#76-43-01A) to address what really should be a recall.
Thursday, February 1st, 2007 AT 7:35 PM