I also bought a pair on impulse and have a similar issue. I scooted them as far back on the rack as I could and that mostly took care of it. Now I only have an issue if I put too much weight in them - they sort of sag forward - so I pack sorta carefully. Post again if the corner trick works for you - I may give it a try.

They are super cute, so I'm willing to put up with a little hassle. Plus, for me, they're really only a summer accessory because they are not water resistant enough for Portland rain!