Well... In C: (Window 7 partition) I got more than 30 GB free, in my data partition (E: ) I have more than 70 GB of free space, i dont list my xp partition because i will not use it... (basically i have 3 partitions, 15 GB for XP, 50 GB for Windows 7 and 84 GB for my data)
I tried too in my laptop, y left the <predefied> option in the file locaton... it was about to burn the DVD... but after trying to do so, it stopped and gave the same error... but now the DVD has written data (corrupted i guess) and now I cannot use it

... lucky of me I bought 3 dvds XD IN my laptp I got anly 2 partitions, Windows 7 with more than 40 GB free, and my data one with more than 150 GB free... (here I have 60 GB for Windows 7 and 172 GB for my data)
I'm getting frightened about this soft... I hope it doesn't f**k another dvd again
See ya!!!!