Okay, let me tell you my little story.
I used to have a big Windows partition and a little Linux partition (well actually, 3 little Linux partitions including swap and the extended one that contains swap).
Since I don't use Windows now, I decided to resize my NTFS partiton to make it smaller and then, enlarge ext3 partition with Linux Mint on it.
Ok, I resized NTFS, but now I can't resize ext3! I have 13.5 Gb of Unallocated space that I can't even use!
I used GParted booting it from Knoppix and Freespire (tried both, but none help).
I made sure that the partitions are NOT mounted, but still nothing!
I'm so frustrated!