[API] Can't download or overwrite a file after uploading it 1 time(android) (have to reload the app)

Thanks! I just gave this code a try, hooking it up to a button in a sample project, and it worked fine for me when triggering it multiple times. I saw all three log statements each time.

I notice you did say that 'the second time only the first one "First Phase" appear', and that 'It look like the async task doesn't start', so it does sound like the issue you're seeing has to do with running the AsyncTask itself, before the Dropbox method is even called. (That is, since the Log call in doInBackground is before the Dropbox call.) I'm afraid I can't offer help with that though, since it has to do with Java/Android itself, and not the Dropbox call in particular.