[CentOS] Stuck at GRUB

Hi,

	I have a Dell poweredge 400SC here with an LSI scsi card.

I installed Centos4 a while ago and put it in a datacenter.  I rebooted 
many weeks after, and the machine didn't come back up.  So I went to the 
datacenter tonight to find out that the server was stuck at "GRUB". 
Nothing more.
	
	So I decided to re-install Centos4.  The partitions were already there, 
so I just made sure partitions were formatted and the install went fine. 
  When I rebooted, "GRUB".

	I'm at this point and I don't know exactly what I could do to diagnose 
furthere.

	Any ideas?

Regards,

Ugo