netinstall method - no disk drive detected

I am using netinstall method for beagleboard Xm.I successfully write boot partition and put card in board.It recognizes ethernet and downloads required packages.
my problem is after password prompt in Disk detect prompt - installer displaying No disk Drive Detected.If you know the name of the driver needed by your disk drive,you can select it from the list.
What I have to do.
I formatted the sd prior to netinstall with ext3 filesystem and after netinstall script it is showing BOOT partition.