I am having the same issue with my stock 17's. When I first noticed this I did check the tire pressure and it was a little low all the way around. I am also going to rotate the tires front to back (I have that option) and see if the same thing occurs on the newly positioned ones.

__________________
2001 X5 3.0i (PP/WP/AP) Traded at 213K miles
RARE White on Black - Why does everyone get Tan??
First E53 with 215s on XOutpost!!