There's fake and FAKE MS's. I've 2 UNKNOWN-BRAND microSD with the Photofast and works great. Yeah, maybe sometimes I've got to format it, but the original Sony gives me the same issues.
Also, the FAKE FAKE (yeah, double fake) MS's, sometimes overheat more. I had one when I used to plug it directly into my card reader, it melted the connectors of the card and destroyed the plastic. Almost lost my card reader.