I installed a tweak off Cydia which lets my ipod touch turn into a USB drive. However when the tweak was creating the disk on my ipod touch (10Gb) it turned off as it was out of charge. So I turned it back on and had the charger in it and started the whole process again. I noticed that the tweak had taken 10GB off my 28GB I had previously, however I can't delete the previous disk that wasn't installed fully and now I have lost 10GB of my memory. Is there any way I can retrieve this 10GB?