Microsoft recently released a patch for those who are using secure digital cards (SD Cards) with Windows 7. If you are using windows 7 and SD Cards you should install this update immediately. Go to Microsoft page to download the patch.
Some users who are using SD cards (formatted in NTFS) with Windows 7 have run into unexpected problem. Even if you are not using SD cards formatted in NTFS, it is still recommended that you install the patch in case you start using SD Cards in the future.
Problem Overview: You have an NTFS formatted SD Card and a computer that is running Window 7 operating system and you use Advance Direct Memory Access (ADMA) to transfer data between the SD card and your PC. During an ADMA transfer process, the secure digital bus driver converts the DMA data structure of the operating system to the ADMA data structure of the SD Card. The DMA and ADMA data structure are also known as descriptor tables. When you transfer data from the computer to the SD card, the data on the SD card may be corrupted. This means unexpected problems may occur when you try to use the affected data again. What happens in background is that the data-length field is 16-bit and has a maximum size of 64K. However, during the data conversion process, the SD bus driver doesn’t check the buffer size in the system’s tables. Because of this, the driver may set an incorrect data length. So corruption in I/O occurs, which cause the data corrupton or data loss. Please visit Microsoft’s site for more details.