Bootloader Fail

Ground
I'm trying to boot my board but I get an error. 

My motherboard is 256MB.
I load the "superboot-20100624" (whit SD-Flasher) in a sdcard to boot.
Then in the friendlyarm.ini I have the code below:

#This line cannot be removed. by FriendlyARM(www.arm9.net)
CheckOneButton=No
Action=Install
OS= Android
VerifyNandWrite=No
StatusType = Beeper| LED
################### Android ####################
Android-BootLoader = Android/u-boot_nand-ram256.bin



..but when loading the boot file I get up the next error:


Installing OS 'Android'
Download bootloader...
Skip block 0x1
Download bootloader failed


What is my problem?