in step 2 you say choose usb connection, i get: 1)internal nand 2)internal emmc 3)(external SD partition) N/A 4)power off (when not connected to a charger) and then 2 more options below: 1)press menu/ctrl for USB mass storage mode 2)press shift for network mode and when i choose usb mass storage mode while connected with usb cable i get a pop up with n900 and SD card folder, then it dissconnects after a few seconds. thats y i cant make partition as mention here to store the image file. can u suggest what i should do. thanks