There are literally dozens of things that could cause a backup to fail, which is why I use either the inbuilt utility or Veritas as they tend to handle things like improper filenames much better than any others.
What I would suggest is schedule a backup operation to a file using the Windows backup utility, then have whatever burning program you use burn just that one file that was created. Simple, elegant and if you need to use the backup no special software is needed, even for a full restore: just load a new copy of Windows, load the backup file and go. Veritas doesn’t have the ease of use, but it is a bit more powerful. I have yet to get anything but Veritas and the Windows one to work properly for large backups to any kind of media be it Zip disks, CDs, DVDs or tapes (tapes especially, nothing else almost works with them for Windows).
How to copy your files from desktops to a server each night? Well, you can do that with no additional software. There are a number of ways to do this, but I’ll cover two briefly, and both work without any special software. The first one is to have each of them run a nightly backup and then some time later use Windows file sharing to either upload the files to a share on the server, have the server download from the clients or (like I do) map a network drive to the server and have it run a backup directly to the network drive. The second option is to make each computers’ C$ share a drive on the server and have it run backups of each machine each night. I perfer the way I do it as it allows more control from the client end and the entire backup won’t fail if one machine is disconnected from the net, but to each his own. Veritas also offers a utility for backup up an entire network with their software stack, and it’s pretty easy to use.
For UNIX systems of course, welcome to the wonderful world of tar. Oh, Veritas works here too.