A while ago, I picked up a 'cheap' 2GB SanDisk Ultra II SD card for my (then) shiny new Canon IXUS 80is on eBay. The price was a bargain, the seller had good feedback, and the photos of the product showed that the item was brand new and boxed. So, I had no hesitations in buying the card.
Last week, the card failed on me. I took a bunch of photos of Aimee on it, ejected the card from the camera and popped it into my desktop. Debian etch's Gnome usually automounts SD and USB media, so I was surprised when it didn't automagically appear on my desktop.
I had a load of error messages in dmesg, saying that the kernel hadn't been able to find a valid filesystem on the device, and the ominous DriveReadySeekComplete messages confirmed to me that the card was toast.
Annoyed, but unconcerned, I pointed Firefox at www.sandisk.com and set about claiming on SanDisk's generous 10 year warranty. I emailed them with details of the card, like the serial number on the back, and a brief summary of what's wrong with the card – asking for advice as to how I'd have the card replaced. To my utter disappointment, I received a reply telling me that the number given was invalid, and that it was highly likely that I had purchased a counterfeit card.