One problem related to ignition module has been reported for the 2003 Chevrolet Trailblazer. The most recently reported issues are listed below.
Power window control on the passenger door started on fire and melted some of the door panel and window control module and wiring harness. The vehicle has the heated seat buttons on the window control module. (p/n 15096223). The vehicle had been parked in front of the house (no keys in ignition) when the window started going up and down by itself and smoke started flowing out. Completely melted the front 4pin connecter and wiring harness I still have the melted part if needed for anything. I found it interesting that you have now opened up an investigation on 2006-2007 models on the drivers door. I had did a few internet searches looking for recalls or such. Did find a couple post where similar things had happened to others where others had stated having to do with water coming in the window and shorting the switch (if this helps) thanks.