Even a small typo can create big problems. Turn on the debug window by selecting Show Debug Window from the File menu. Start another file transfer by hitting Cmd-T. Watch the transcript window for error messages that might provide a clue. You might see something about a bad password, unknown user, or unable to connect to the host. Double check the user name and password.
All fields are case-sensitive.
Try setting the path to blank and see if the files will transfer to the root directory. Set the destination number of images to 1. This keeps things simple. Use Fetch or Anarchie to double check the results by downloading files that you have uploaded. Just remember that image01.xxx is the most recent.