I've just made a german translation for your plugin and I found some little "bugs" in the code.
- bp-media-template-functions.php, line 8: "(Max File Size:" is not translatable.
- bp-media-loader.php, line 83: load_textdomain() should be called at the top of this file, otherwise the label constants (line 25) will not be translated.
- bp-media-loader.php, line 85: You use load_textdomain instead of load_plugin_textdomain. I don't know if this is necessary (bp itself does the same), but if not, you should use load_plugin_textdomain.
- Just a quick note: you haven't documented that you plugin is translatable and there is no /languages directory and no .pot catalog. I think many users will not know where the files belong.
Are you interested in getting the german language files?