Although in theory it is possible to fake out the server and lie about what browser and operating system you have, that does not ensure that it actually will work in your browser. Please see this earlier thread: https://support.mozilla.org/en-US/questions/750405#answer-276368 According to a post I found somewhere, SAP apparently also have a tech note 1618309 - IE9/FF4 and IE/FF support on Web Dynpro Java and commonly raised issues. Without passwords for the SAP marketplace, I can't read it.