It's not a physical lock, the end of the card snaps underneath a lip - you have to flex it quite hard to bend the card.
Thanks for the warning though Iain. I tired the card in a number of Kodak cameras, a Fuji and a Ricoh all without problems. As soon as a Canon crosses my desk I'll try it in that and see what happens.
That doesn't sound very good. I mean I was going to buy a Canon but it doesn't sound very good if the cards get stuck in them. Can you get them out again?
So I checked with SanDisk...their spokesman told me "this is a problem with a very very very small percentage of cards" and that they are working on a solution.
OK it's taken a while but finally I have got all the bits together to check this out.
I have just tried one of the SanDisk Ultra + SD cards n a Canon A620. There were no problems at ll- the particular camera and card I have tried work fine together.