Hi: I have a Ativa brand (Office Depot store brand) SD/SDHC card reader. On my home computer, which is a HP dv9925nr 4GB RAM running Windows Vista Home Premium 64-bit, my card reader causes my machine to run very slowly when I insert a Patriot memory 16 GB SDHC card in it. It runs up to 8 GB cards OK. The computer does eventually recognize it but it runs too slowly for me to open files. Fortunately I can use the built in SDHC card reader on the computer but its the point. Now, at work, I use a Dell notebook computer that runs XP Professional. That one accepts the card reader / 16 GB SDHC card just fine. So it isn't the card reader or any capacity limitations or anything. I'm thinking its some kind of driver missing or other conflict with Vista 64-bit. Incidentally, a slightly older but very similar type card reader from Ativa does run this 16GB card OK. Also, I bought a 2nd one - same kind - and it also has the same problem. So its not isolated. Ideas?