While I was testing out ruby-dropbox-sync I saw that my files and folders were succesfully synced, but they were all missing the first character in the file/directory-name. For example 'Projects.wiki' became 'rojects.wiki' in the dropbox folder. When I ran the sync again (using cron.rb) it became 'ojects.wiki'.
In config.yml the :sync_dir: ended with a slash. Removing the / at the end of the path seems to have fixed the issue.
I also get a warning when running cron.rb, but I guess this is of no importance for this issue:
[WARNING] MultiJson is using the default adapter (ok_json). We recommend loading a different JSON library to improve performance.