Whirlcool, my Mirro dates back to the 60's but is super low mileage for a cooker that old. I guess at some point the lids maybe do warp in that same spot if you're having the exact same problem. You must have had plenty of water in yours to allow it to go for 10 minutes before sealing itself. I would have been out of water by then for some of the things I cook and that's why I had to keep an eye on mine. No danger of it blowing up if it has a leak, but you'll smell your food burning pretty quick!