majorsilence

In the following FAQ:

Generic-3:
Why can't I use a VFAT/FAT32 partition to create my DVDs?
VFAT and FAT32 file systems doesn't understand uppercase/lowercase letters, and shows everything in
lowercase. Unfortunately, the creation of a DVD tree is case sensitive.

A better response is that VFAT/FAT32 cannot handle files large enough for a DVD. DVDs hold 4.7Gig. The maximum file size for FAT32 is one byte less than 4Gig. Therefore, you cannot create a full DVD image on VFAT/FAT32.