Microsoft released an update for Windows 7 that fixes a data corruption issue that occurs in Secure Digital (SD) cards. “You have an NTFS formatted SD card. You use Advanced Direct Memory Access (ADMA) to transfer data between the SD card and a computer that is running Windows 7 system. When you transfer data from the computer to the SD card, the data on the SD card may be corrupted. Additionally, unexpected problems may occur when you try to use the affected data. During an ADMA transfer process, the Secure Digital Bus Driver (Sdbus.sys) converts the DMA data structure of the operating system to the ADMA data structure of the SD card. The DMA and the ADMA data structures are also known as the descriptor tables. The descriptor table contains a data length value and a buffer address. The data-length field is 16-bit, and has a maximum size of 64K (kilobytes),” KB976092.