I normally like to capture my reference images from a virtual machine as it eliminates a lot of the driver issues you have if you capture an Actual machine. I did sometimes run into problems capturing XP images though. The build and capture posses would work fine, but once I deployed the image (with Storage driver and HAL replacement scripts and everything ) it would just enter an endless loop ether before the minisetup, or just after.
The problem turned out to be the old UberBug problem where WinPE 2.1 formats the HD in a way that XP doesn't really care fore. The solution is very simple... Just add the OSDDiskpartBiosCompatibilityMode = TRUE variable just before partitioning the disk, and it works.
And remember, as long as you deploy XP using SCCM and WinPE 2.0 or 2.1 you should set this variable on you capture TS as well as your Deploy TS.