I tried your credit card tool method and, as you say, it does work like a charm. It is certainly a better tool than paper clips or other sharp objects, which might damage the rubber seal. The only problem I see with your method is that it puts a credit card in my hand. I try to avoid that since I might be tempted to buy more camera gear. I recently paid the credit card charge for the D800E and I am still smarting from that blow. Thanks for the credit card tip.