Just upgrade the bios A17, can not downgrade to use DELL.LATITUDE.D630.A16.BIOS.SLIC21.UPDATETOOL.BBSC.rar
Original BIOS location: http://ftp.us.dell.com/bios/D630_A17.EXE
Original BIOS location: http://ftp.us.dell.com/bios/D630_A17.EXE