Here's one for everyone to cogitate over: I'm using Toast 7.02 on a Mac G5 1.8 MHz and OS-X 10.4.6, with 2GB RAM.

I am attempting to backup tens of thousands of files onto DVD, and Toast takes forever to get started. The last DVD I started Friday afternoon, & let my machine work over the long Memorial Day weekend. As of this time, 5/30/05, 1358 EDT, it still hasn't started burning, and it is using 40 - 60% of my system resources. My machine never sleeps, but the screen saver comes on after 30 min of inactivity.

Anybody know why this occurs?

Well I would turn off the screen saver first. Almost every other process slows to a crawl when the screen saver is on. Second, I would start the process over and choose to burn to an image file, rather then a disc itself. I have never tried to burn 10s of thousands of files before, but it sounds like a pretty tall order.