Basically, there isn't much depth behind the drywall before I hit the outer wall. Well, the short screws gave way with all the pulling on the drapes being slid open and close.
The solution? Deeper screw penetration! How do I know that would work?
Funny story. Years ago in a prior life I was chasing a roommate through the apartment. He closed and locked the door. No problem. I ran right through blowing the door and hinges off the casing. It was explosive. Scared the bejesus of my roommate who thought he was safe!
Anyway, came time to fix the door and I wasn't sure how to get the screws back into the holes I had just ripped them out of. The super shows up and without a worry on his face just used longer screws to get deeper into the wood.
I applied that lesson here. Success!