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isn't the updater.jnlp file on your desktop the one you start ender's client with ? The one that shows this:
That is the one you are supposed to start the client with, after swapping the salem.jar in your Salem/bin folder with the listed one. Right now i'm not planning for an easier way to allow the use of my client, but if more people have troubles with the installation that might have to be done after all.
You can hit me up on irc if you have time, and i'll try to get it solved with you