With Firefox the filereference object returns something
different than IE if I got it right, I'm having trouble getting
upload() to work with FF, seems it doesn't pass the full path and
filename to the uploader, only the filename so it bombs. Something
like this may be your problem ... not sure but seems it could be.
Haven't found a fix yet, have been trying to add a
conditional to catch that the path is missing (or detect the user
agent), that's easy enough but I haven't found out how to get the
path to add to the filename before calling upload.