Fail to expand Yun disk space , got err. formatting to FAT32

I try to follow the step on , http://arduino.cc/en/Tutorial/ExpandingYunDiskSpace , to expand the Yun disk space.

When I come to the Proceed with partitioning micro SD card ,
I got err. formatting to FAT32.

I use a Kingston 8GB class 10 micro SD card.
Please help.