Also, read the (sticky) warning posts re. INCD at the top of the post lists.
For the marginal benefit that you gain using UDF disks, the risks seem too high. I invested in Norton Ghost for doing backups, and have restored from it several times with 100% success.
Ghost has the facility to split backup files to a maximum size (say 1 GB - max 2GB). I prefer to set to 1 GB and doing a full C drive backup get 6 files of 1 GB each (last is smaller).
I then copy no more than 3 to a DVD using iso standard ISO format using Nero (not INCD UDF format). The reason I only burn 3 to a DVD is that simply I have found DVD verification failures often occur in the last (outermost) section of DVDs. Thus burning 4 GB is sometimes hit an miss. 3 GB always seems to work.
Obviously this depends on media quality. 3 GB seems to work on virtually all disks though. As media is so cheap these days, this is no big deal.