Next time, tell us your hard drive partition scheme, ok?

It´s not a good idea have Xp and leo in the same drive, not always happens but leopard can cause a lot of problems (corruptions), anyway open Xp and run chkdsk if all is ok boot with -s and type

mount -uw /

cd /system/library/extensions
mv ntfs.kext ntfs.kext.backup
reboot

boot with -f -v