Dual booting XP & Vista already vista installed, Can not load XP

After shrinking the HD it created 62.39gb as D: vista as C: (160GB) & 10GB is builtin restore os. total size 250GB ATA .
Once boot the system with XP prof. to load, recieved an err msg UNKNOWN DISK - There is no disk in this drive.
No problem booting vista atall , all partitions can be seen. Tried to run 'Check Now ' option thru Tools were successfull ...reboot the system & tried again to load XP, Recieved the same message as mentioned above.
There is no problem in booting vista, all partitions are there & can be seen.

HW is Gateway t-series Laptop.
Help requied ....Thanks & Appreciated