Using create_sdcard.sh in virtual box ubunut 12.04 failing(sitar linux sdk)

Hi ,

Intermittently I am getting an error like this when trying to use the create-sdcard.sh script.Can you provide some inputs to resolve this.

./create-sdcard.sh: 354: ./create-sdcard.sh: [[: not found
/dev/sdc is an mmcblkx device
./create-sdcard.sh: 364: ./create-sdcard.sh: Syntax error: Bad for loop variable
manojkdi@manojkdi-VirtualBox:~/ti-sdk-am335x-evm-07.00.00.00/bin$

Regards

Manojn