<center><img src="http://photos21.flickr.com/25995892_ee09da9632.jpg?v=0"></center><p>
taken with a Canon Elan 7e, the lens is a 24-85 USM f3.5

Polarizing filter is on.

Notice on the right side that the corners are dark, while the left side the corners are tan.

Is it the filter? I've a few other pictures where there is viginetting on all corners in black with the same lens, when shot at 24mm.

Sorry for the crappy pic size, it's hosted on Flickr.com

couple of ways to address this would be to not use the filter when you're shooting at 24, or getting a slim polarizer filter...

are you stacking the polarizing filter on top of a UV/haze filter or anything else?

I thought maybe it was the lens hood, as I thought I had the same viginetting on shots without the polarizing lens. I'll have to double check- that's a good theory.