[CentOS] install detecting disk as sdb not sda

Fri Feb 3 17:24:14 UTC 2012
Jerry Geis <geisj at pagestation.com>

I am trying to install 6.2 on a machine.
I am using PXE as I have done so a number of times.

My hard disk is being detected as sdb and not sda.
My kickstart config is wanting it at sda.

There are no other disks in the unit. It has and SD slot and an esata
although BIOS does not appear to have a disable for either of those devices.

Is there anyway to "force" the disk to sda ?
or find out what its detecting at sda and disable that from the PXE boot 

Doing " dmesg | grep sda" does say SCSI removable disk.

So how can I tell linux to NOT include that when installing?