Your mobo may require you to provide XP with SATA drivers during the installation. I'm not too sure myself, since the only time I installed windows on a SATA was on a friend's comp, and nothing extra was needed (was also a sp2 installation).
I believe while the windows installation loads off of the cd (while booting), you have to press f6 or f3 (or maybe f4, one of those keys, in any case). Then you pop in the driver disk that came with the mobo and load the SATA drivers.
Edit: On the abit driver download for your mobo, there is a VIA SATA driver and a Sil3112 driver disk file. Try loading both onto a floppy, and load them when installing XP. As for which key you need to press, when you boot to the installation cd and the blue screened interface pop's up, there will be a message at the bottom saying "press [this key] to load a 3rd party disk driver" or something like that.
If you don't have a floppy drive, you'll have to slipstream a windows installation with the drivers using a program like nLite, so they'll be on the installation cd to begin with.