I am trying to transfer files from a thumb-drive to my phone using a Windows 7 PC, well it seems to be going alright and then it just hangs at like 10 seconds left of the transfer and i eventually have to cancel the transfer, but then sometimes after canceling the transfer it shows that the file has been transferred.. Also for some reason the PC is not detecting my phone all the time, sometimes it will detect it and sometimes it will just stop, and say that the device has stopped working or been unplugged, even though neither is the case.