I went to Shenzen, China yesterday and found a Sony branded (surely fake) 128gb flash drive which I bought for 150 yen (20usd). The sales person showed me that it worked in the shop but when I brought it home I had some problems. I was expecting this but 20usd was a risk worth taking! The usb works fine for small files and I can transfer large files to it but when i try to transfer them back to the computer, the transfer freezes after a short while. It varies how quickly it freezes, anywhere from 1kb-300mb so far. I have tried numerous different formats on it. When it freezes and has been formatted in any of the mac formats it needs to be reformatted when i plug it in, but not when its in fat32 or fat64. Is there any way to fix this or is it a mechanical problem?