When I was installing Mint Debian edition unlike the classic edition, the installation automatically formated my home partition when I did not specify to format.
So the formatting previously was ext4 ...
In every publication I found about ext2, the structure of a block group is defined as following:
Super Block: 1 block
Group Descriptor: N blocks
Data Bitmap: 1 block
Inode Bitmap: 1 block
I've reinstall windows 7 on it's asignated partition and, as usually, it override the MBR with it's own stuff and, thus, it was not possible to boot to my ubuntu 12.04 partition.
I followed the step ...