Shashin won't add/update albums

When I go to Admin > Tools > Shashin and enter the path to my albums in the Add Albums section (in order to add latest albums to Shashin), I get the error message “ShashinAlbum::setUserAlbums – Failed to parse album feed.” I am entering in the form of http://picasaweb.google.com/username

However, the existing galleries continue to display fine.