Great work @gboyd! You're solution worked for me too.
I didn't have the Revo app, so did a manual search in a few key folders:
1. Uninstalled app
2. looked in c:\user\....\AppData, searched for 'evernote' and deleted the folders
3. downloaded fresh version and installed.
4. login, sync works fine
Would be nice if the uninstaller gave you the option to remove all this 'local' data. It's always annoying. When i say uninstall, i want the whole thing gone, not leave bits and pieces - or at least give the me the option.