Dude.. (david)
I thought I was the only 2006 Mazda 3 with this problem :) Glad to hear I'm not alone.
I started a thread on this subject here:
[http://www.mazda3forums.com/index.php?topic=107069.0|Forum Link from sdhartney]
I'm currently fixing this problem for the second time.. but I ran into a snag.. the motor got indexed wrong and now thinks the glass panel is "up" in the rear.. I have to try it in all positions until it re-indexes correctly.
So.. tell me.. do you have the sport tune suspension? and low profile tires? and drive lots of miles? and live in a dusty area?
All those apply to me, so I'm wondering if there any common conditions that cause the roof movement to stiffen up.
Steven