At times, a catastrophic event (such as a power outage) that interrupts recording will result in a damaged Quicktime® clip. Generally, such a clip can be repaired by simply adding it to a DDR playlist. (Note that this process depends on the clip being stored as-is within the NTFS file system at all times before repair. Operations like zipping the file, transferring it to a FAT32 drive and then back, etc., will make recovery impossible).
For more information please download the entire document at new.tk/rt-m