I have tried burning an iMovie that I saved onto the desktop on my Mac. The first copy came out fine, but when I went to do a second copy (yes, I am THAT mother that fears one will stop working and then those memories will be lost forever), I have gone through 5 discs with the following error message: "The drive reported an error: Sense Key = ILLEGAL REQUEST, Sense Code = 0x21, 0x02. BUFFER UNDERRUN." I am new to using this, and am very frustrated. What am I doing wrong? How do I get this to work? Also, I did restart the computer and the program in between. I am using an Apple SuperDrive to burn it. Please help!!!