Well my gut says that is probably your problem. Since you say the Screensaver hack didn't work, I suspect that he installed the wrong one for his device - for instance, maybe he tried to put the Kindle US file onto the Kindle International device?
My best guess is that you are going to have to find the right uninstall BIN file for the screensaver hack file that he trued to use, apply that, and then apply the update.
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