Well... I've found that I can almost always get CDArchitect working successfully by using "ATAPI MMC Compatible" as the drive choice... but no more. In WindowsXP, none of the appear as selectable any more. It's time to look for another company I guess. That's really too bad.
For starters, I started with a clean install of XP. Upgrades seem to cause a problem, especially if you have CD burning software already installed when upgrading. Remember XP is still in beta. The ASPI layer in XP after a fresh install is not complete when using Adaptec's ASPI check utility (it's not in ME either, for that matter). If you do not have Adaptec ASPI drivers installed, the update file from them will not install as it checks for valid Adaptec drivers.
The best thing to do is a clean install of XP, then update your motherboard drivers first (if necessary). Then install the ASPI layer before anything else. Reboot when prompted. Then install CDA and see if it works.
Also keep in mind that CD Architect was never tested under Windows XP, so there is no guarantee that it will be compatible. CD Architect is only supported under Windows 95, 98, and NT.