I have a powershot a620 and the underwater housing- the wp-dc 90. On my first trip I used it on several dives and had no problems. On my second trip, after 8 dives and lots of snorkeling, I noticed a few drops of water leak in through the lens area. The main o-ring was never an issue, it always sealed tight. To be safe I always tested the seal before each dive, and cleaned the case well after each use. The drops of water weren't enough to damage my camera, but I stopped using the housing after that. Right now it's at a repair center and I'm waiting to hear how much it will cost to fix it. Despite the leak, I will probably get another one if it is too expensive to repair.