Closed Issue: AutoCompleteExtender flashes then erases then draws [16434]

I'm working with this control, and just love it, but it tends to blink at me from time to time. It will draw the drop down skeleton, erase it, then draw the correct drop down. This is the default behavior out of the box. I've been digging through the code, but can't find why this is happening. Has anyone found out why the control is doing this, and how do I correct this? In theory, it should stay hidden until it is completely drawn, but that is not what it is doing.
Comments: We tested this control in all modern browsers and did not detect the described problem.