Unresolved storage problem

A couple of weeks ago i noticed the storage of my 4th gen Ipod touch (GB), taken by " other" , almost 2.5 gb of my ipod was used by this kind of files. After trying a lot of stuff i finally gave up and decided to restore the device.Now that i restored the ipodto the new ios 6, using the standar procedure my itunes marks only 0,54 gb of other, but the overall capacity of the device according to my itunes is only 6.38GB not 8GB, so there is still something taking almost 2gb of the storage of my itunes.

I dont know if someone is going to answer this, but i will like Apple to solve this because there is a lot of people having the same problem.