refreshOAuth2Token got the following response:
{ "error": "invalid_grant", "error_description": "Bad Request" }using refreshToken 1/9QG-OrDSX3h5yYaTVCQf_1P0SfBvFhnr2HTUzbXwsfwMEudVrK5jSpoR30zcRFq6

You can also see the gallery at Picasa