Bios : error 1962 /boot sector

Hello
i try to install a linux OS on a Xseries 205 , it works fine when i do
my installation is done.
But when i reboot my system, the server can't boot because he could not
find boot sector :
"1962 Driver does not contains valid boot sector"
It was strange cause, it works with another systems a few weeks ago.
I ve try to change jumper settings etc... (cable select, master,
slave)... it doesnt work.
I ve took the hard disk and put it on another server, it works fine....
If anyone can help me to solve this trouble.
thanks in advance
Patrice