Small Form Factor SN95G5 sata boot problem

I have a Shuttle XPC SN95G5.. I've been using a normal PATA 60 gb hd in it and now I wish to more to using only a 250gb Western Digital SE SATA drive, which i have.
I've tried installing Windows XP 64 on it and the HD seems to not be bootable at all. Checks, formats drive, copies files reboots and then says error reading OS.
Is the SATA interface on these kits not bootable or is there something wrong with my drive - I've updated the BIOS and still no joy.
I also tried ghosting windows xp to it from the PATA drive.
Any ideas as it's driving me insane.
Ta