4.7 GB Gutsy Gibbon DVD Image won't fit on my 4.4 GB DVD Rom

Help! I'm new to burning DVDs in general, so there could be something
pretty obvious I'm missing here. I'm using Windows XP.
I have a Mad Dog MetaSTOR DVD burner, and Memorex 4.7 GB DVD+RW
rewriteable disks.
I downloaded Edubuntu Gutsy Gibbon, based on Ubuntu 7.10. As this page
shows, this is a 4.9 GB iso file.
http://cdimage.ubuntu.com/edubuntu/dvd/current/
I loaded my downloaded iso file into an emulated drive using Roxio's
Disk Image Loader.
I fired up Roxio Creator 8.2 XE and put a disk in the MegaSTOR. The
disk capacity is reported as 4.4 GB. I go to Data/Copy Disk, selected
my emulated drive as 'copy from' and the MegaSTOR as 'copy to'.
Of course, this fails. There's not enough space. Windows Explorer
reports the size of the emulated drive as 4.87 GB.
Am I dead in the water here? Should I just download the CD images and
burn those onto my DVDs? I find it a little suspicious that this very
popular operating system's DVD image is larger than my very standard
DVD. The image itself is only 3.62 GB, so I wonder if I can't squeeze
it onto my DVD somehow.
Thanks for your assistance!
Ion

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