
It´s my 4G sdcard. I have one 1G sdcard that I "part" the same way. I always use gparted, because I get confused with fdisk, because my system is based on proportion, not size.
I always take first 20M (gray on picture) for MBR+u-boot+uImage+uramdisk.
My next step is to take 1/4 for the first partition - FAT
more 1/4 for first ext4 partition - system
more 1/4 for extended partition - 1/2 and 1/2 each ext4 inside it
and, everything else (another 1/4) for last ext4 partition.
Even then I have this sdcard partition, my Ubuntu detects every partition (and mount it automaticaly). Please, make sure your ubuntu create /dev/sdX even if ubuntu cannot mount it on /media. You can dmesg and see if it´s right.
Try to not recreate MBR (partition table).