Here's the response from Cookware 'n More (fyi, it is not a
slight concavity). I'll try All-Clad tomorrow:
Bonnie,
Any good fry pan has a very slight concavity, because when the pan heats it will expand and flatten. Our irregulars are cosmetic defects, things that do not effect the performance of the pan. If the pan is used you have to go through All Clad for your warranty, which is a full lifetime warranty against defects that would effect your performance. You can contact them at (800)272-2170 or through their website
www.all-clad.com. Please let me know if you have any other questions. Have a nice day.