Microsoft issued an update designed to take care of three problems associated with Universal Disk Format (UDF) file system driver (Udfs.sys) for both Windows 7 RTM and Windows Server 2008 R2. Microsoft described first issue “You try to back up some large files to a DVD-RW by using Windows Backup in Windows 7 or in R2. However, backup operation fails and you receive an error message that resembles following: “Logical Block Address Out of Range (SCSI_ADSENSE_ILLEGAL_BLOCK). Second issue “You format a DVD+/-RW in the Like a USB flash drive format, and then write some files to DVD+/-RW. After you eject and then re-insert this DVD+/-RW into DVD+/-RW drive, you cannot write a file to this DVD+/-RW. And third “You format a DVD+/-R in the Like a USB flash drive format. When you try to write files to DVD+/-R, writing speed is very slow. For e.g., on a computer that’s running Vita, it takes about 20 seconds to write a 100MB file to a DVD+/-R. However, in Windows 7, it takes several hours to write same file to a DVD+/-R,” KB975617. A supported update’s available from Microsoft here.