Front camera is working properly.
Before this problem have appeared I had mounted the internal sd card as Mass Storage with SD Mounter.
I've formatted sd and I've copied all the files again, but I still have the same problem. I also have done a factory reset with equal results.
I don't know what else I can do.
I'm having a rooted stock version (4.1.2).
Could it be a problem writing/reading on internal sd ? How can I solve it?