If you are having problems with the free space on the iphone restore your iphone using itunes and then unlock it with ziPhone ( http://www.ziphone.org/ )

I have this problem because the space from OTHER was over 6GB and I can't sync almost any music or photos, I try deleting everything from the iphone and that don't work.

When you press the restore option itunes is going to tell you to make a backup.

I upgraded to version 1.1.3 via itunes and I have no issues when I made the restore and unlock the iphone using ziPhone.