It certainly sounds like you scrambled the Super-block to that drive. It
sounds like it got unplugged at the worst possible moment. If you still have
the files on the source machine I'd just format the USB stick and start over.

I'd try fdisk on it (on the Linux machine) and delete the partition(s)
on the flash drive, then recreate it/them. I'd probably do the
formatting of the file system on the Windows machine, as I've (on rare
occasions) had flash drives that I've formatted on Linux machines not
work quite right on Windows machines.

They are usually formatted in FAT 32 from the vendors. At least the ones that
I own are and from other reading on the web that seems to be the consences.
Later....

I'm not quit sure what the point of you post is, in light of my trying
to help Graeme get his to work again. I didn't ask what file system
was used on factory formatted flash drive after all...

More info on what I have recently done with flash drives, for those
who are interested:

The first thing I did when I got my 2G Lexar was to delete the factory
partition, create two new ones, format one for Windows, and format the
other ext3 for Linux. Works great.

I think I did the Windows formatting under Linux with mkfs.vfat, but I
can't remember. I formated a little 128M generic flash drive that way
the other night, and I could use it on one Windows machine, but my
wife's laptop couldn't see it, and I had to reformat it on her
machine, then they both could see it. I remember this happening at
work some years back as well. Works on some machines, not others.
Every other time I can think of that I've formatted a Windows
partition with Linux, it has worked out.

I can get away with simply reformatting the thing can I? I was unsure
about this - my knowledge of these new-fangled USB thingies is
somewhat limited ... I was concerned that I might do more damage
than I've already done by doing this.