烧写nk文件时总出现效验错误

我下载的是2010年6月 最新TQ2440光盘

按照说明，现在Nor下刷完stepldr、eboot、logo后关机，转为Nand开机进eboot

然后b->9->u刷nk文件，但总是在最后一步出现如下错误，镜像是光盘里的出场镜像。4.3寸屏

Enter your selection: u
USB host is connected. Waiting a download.
Addr: 0x3000000 ; Size: 0x1ED2BA5Read Bin Files StartAddr:0x80200000 ; Length: 0x1F44084
Download BIN file information:-----------------------------------------------------[0]: Base Address=0x80200000  Length=0x1f44084-----------------------------------------------------+=OEMVerifyMemory+ dwStartAddr:0x80200000  dwLength:0x1f44084 RAM image 0xa 0x82144083ERROR: Checksum failure (expected=0x1BDA06E  computed=0x1BDA06F)****** Checksum failure on record 3, ABORT!!! ******

把NANDFLASH格式化之后再烧写。