I ordered two of these as I'd never had a problem with Kingston products and trusted the brand, having used their CF cards for years in my Canon 350d without a single problem.
However, neither of the SD cards I ordered worked with my new Canon EOS 650d. They would read/write in a computer and worked in a Powershot S95 but they refused to play with the 650d even after multiple attempts at formatting on different devices. As soon as either card was inserted, the 650d gave a 'card not formatted' error.
The 650d worked fine with two different Sandisk cards that I had lying around, and now also works fine with a Sandisk card I ordered to replace the Kingstons.
Maybe it's a Canon problem, maybe it's Kingston. Either way if you have a 650d and are thinking of buying one of these Kingston cards, I would suggest going for a Sandisk card instead.