This isn't a step-by-step "how to" but more of a "how not to."
I had heard a Windows Weekly podcast where Paul Thurrott talked about an article he had written on how to create a Windows XP installation disk with SP3 slipstreamed into it. It is nothing if not thorough.
Paul wanted to make his process completely self-defining and using all free software. So he used ISO Buster and Nero 8 Trial.
ISO Buster is used to extract the file Microsoft Corporation.img from the original XP disk. As I'd already built an SP2 slipstreamed disk a couple of years ago, I already had that. Scratch off ISO Buster.
And I am a moderately big fan of Roxio so I didn't need Nero 8 Trial. Sometimes I'm too "clever" for my own good.
The end of the story is that the Microsoft Corporation.img file that I had worked fine but I had fits translating Paul's instructions for Nero 8 Trial into Roxio-speak.
I googled "make a bootable cd with roxio." On the first page was a link to "The Elder Geek's" post on how to slipstream SP1.
But at the bottom was a link to how to burn the CD using "Roxio Easy CD and DVD Creator 6."
Bingo. That worked.