You must need to know that... for DVD disk... even say 4.7GB... that mean 4,700,000kb... but for computer, 1MB = 1024kb therefore... 4.7GB DVD around 4,589 MB... of course, some DVD disk may be NOT full 4.7GB
And also, even your disk have 4400MB, you still need to have some space for the disk closing... therefore, you can burn around 4150 ~ 4250 MB data only!!!