card sd read error!

[liwei]

thank you for your attention!
 
i have a 1G micro SD card, i format it one partition with vfat.
and i under uboot execute mmcinit ,it show below:

# mmcinit       
cmd 0x8, arg 0x1aa flags 0x75
Error after cmd: 0xfffffffc
Card Type:          SD
Manufacturer:       0x1b, OEM "SM"
Product name:       "SMI  ", revision 1.0
Serial number:      511393319
Manufacturing date: 7/2007
MMC/SD size:        499MiB

i try to format 3 times ,but there is no change.
who can help me ? i will appreciate for you.
thank you.