rear drum brakes wearing more, side to side

[Woogeroo]

A few days ago I was doing some brake repairs and other maintenance. I rotated the tires and while I was at it, I checked the wear on the drum brakes.

I replaced the all of the brake shoes front and rear, in July 2005. A little more than 10,000 miles ago.

The rear brake shoes on the driver side are in great shape, plenty of wear left on the shoes.

The rear brake shoes on the passenger side are down to the rivets and the shoe pad material itself is cracked. !!!???? I'm guessing something is dragging? My e-brake maybe? What else is there to check? I'm at a loss on this one, but my experience is much less than that of many of you guys on here.

The front shoes are fine on each side.

Thanks for any advice or things/ways to check.

-W