So we have had this 5100cn setup and running for a few months now, it's hooked up via ethernet.  So a new project comes along, and I realize the ftp printing option will be ideal. So, I login to the printer with an ftp client and start dumping files over, they are all canceled by the printer.  I try to put over .txt, .doc, .xls, .jpg, you name it, I tried it to all with the same result.  
 
Also, I attempted to apply a password via the web setup and then could no longer login with admin/mypassword.  Is there something I'm missing here?