I'm having the same problem sort of... I'm trying to backup about 12 gigs of files to 4.7 gig DVD+R's . My first attempt backed up data to one disk and then hung up for several hours. I was never prompted to insert a second disk. I rebooted and tried again. This time I got one disk burned and the second one got started but now its stuck at 81% complete on disk 2 and has been that way for hours. Task manager says that the backup up is running but nothing is happening. Why is is this hanging? I'm running Windows XP with my drive formatted as NTSF.

Do you have an external drive you can try to backup to. If you do and that works, it may be a media problem. Also verify you have the latest firmware for your drive, and this update may help.
http://docs.sonic.com/support/px/pxengine2_08_40d.exe