I read the older threads about this..but it only started happening to me recently (!) every movie Im burning now it wont let me. The movie files are either 4 GB or way under..NeroVision is havin a fit with all of them. I have about 500gb free space on my HD! The blank discs Im using are Philips DVD+R 4.7gb but it seems no matter what size of movie it says theres not enough space. I've been burning movies for over a year with no problems now this..what the heck is goin on!
what movies? what programs are you using to backup the dvds? have you tryed a clean reinstall of nero need a little more info
try a burn with imgburn either iso / or files (build mode) whats your project setting in nero for output size? 4300meg?
Is your hard drive partitioned? If you are using Nero Vision, I am assuming you are converting from something like AVI to DVD?
Try Start>Accessories>System Tools>Disk Cleanup. You probably have some data hung up in your Windows Memory and needs to be flushed.