So we have a Regalo gate for the top of our stairs...

http://www.amazon.com/Regalo-Stairs-Expandable-Metal-Mounting/dp/B003VNKLI4/

We have a wall on one side and a banister on the other, so this gate seemed perfect. My first attempt at installing it, I think I drilled into the drywall instead of a stud, so it came out of the wall pretty quickly. We then reinstalled closer to the edge and it certainly FELT like I was drilling into a stud (about 1.25 inches from the corner). BUT it's come out of the wall AGAIN! What am I doing wrong???