Mine Too!!! Since day 1, it's an epidemic!
Always use a rock Bigger than the pipe opening, you DON'T want to suck one into the pump.
Also, try to find a rock that will NOT block the opening if it happens to dump out or the basket happens to break due to age, I just went around the yard picking up candidate rocks and ran each through tests to see which would cause the least amount of issues in a worst case scenario.
Good luck with the patent - got 100,000 dollars to get one in every country otherwise you're just advertising your idea to the big companies who will steal it before you get a sketch on paper!