[U-Boot-Users] The command of nand write cannot write zImage to nandflash

Hi all: I patch NAND (including boot-from-NAND via steppingstone) support to the S3C2410 SoC code in u-boot(http://svn.openmoko.org/trunk/src/target/u-boot/patches/uboot-s3c2410-nand.p...). The u-boot-1.1.6 print the nandflash info to DNW,and the command of "tftp 0x31000000 zImage" is ok,but the command of "nand write.jffs2 0x31000000 0x2030000 0xc0000 "cannot write the zImage of Linux 2.4 to the nandflash and the u-boot print "Bad block check failed". When I excuted the command of "nand write 0x31000000 0x2030000 0xc0000",the u-boot print "0 bytes writed". Can you give me a hand. Thank you very much!