Wrong Way Corrigan? With SanDisk, Hoodman, and Promaster

A client rang with a problem concerning her memory card. The camera she was using had suddenly given her the message " Card Locked For Writing ". The camera had been reliable before, so she suspected the SD card.

So did I. I asked her to take it out and to check the little sliding switch on the side. I did the same, with a SanDisk card in front of me. When she tried the switch on hers - a no-name card purchased overseas - it proved to be locked when the San Disk was open, and vice versa - the switch was in reverse.

Eventually she got going again, took a picture while we were on the phone, and we parted happy. But I am puzzled. I checked all the other cards here in the shop - Hoodman, Promaster, and SanDisk - they all lock in the same way. I should have expected it to be a standard of the industry.

But are there different switches on other cards? Answers from our readers, please - the Facebook connection is the easiest way to do that.