I have all A-Data SD and SDHC cards. I've had one 4GB SD card fail within a year, and they replaced it. I also had a 8GB SDHC card that failed after 18 months, but I'm probably pretty hard on them. Replacing it was so inexpensive, I didn't bother trying to return it. A new 16GB card was only a little over $30, nearly 50% less than what I'd paid for the 8GB.