Have you tried different USB ports? Sometimes it's a hardware issue. I sometimes have issues with one of my front USB ports.
Also, while the device is plugged in, please paste the output from
lsusb between [code][/code] tags. Do you recognise your device in the list?Also, also, what is the device exactly? The model string, the brand, etc. Something we can research, in-case there are known issues with it or at least with it in Linux.
Also, also, also, flash drives aren't that robust, so it's common that they simply stop working, especially if they've been heavily written to — in other words, it's quite possibly a hardware fault on the drive's side. I'd go so far as to say it's the mostly likely cause of this problem, short of a problem USB port. Can you test the drive on a different machine?
