Ultimate Facebook translation problem

Hello.

It seems that the translation for UF is not loaded for me.

If anyone else here has successfully translated this plugin, please let me know where you placed the mo file. I've tried with wpmu-dev-facebook-sv_SE.mo and just sv_SE in the plugins language folder.

Looking at the code, I'm not sure what this does:

if (is_multisite() && defined('WPMU_PLUGIN_URL') && defined('WPMU_PLUGIN_DIR') && file_exists(WPMU_PLUGIN_DIR . '/' . basename(__FILE__))) {
define ('WDFB_PLUGIN_LOCATION', 'mu-plugins', true);
define ('WDFB_PLUGIN_BASE_DIR', WPMU_PLUGIN_DIR, true);
define ('WDFB_PLUGIN_URL', WPMU_PLUGIN_URL, true);
$textdomain_handler = 'load_muplugin_textdomain';

I run a multisite but the plugin is not in the mu-plugins dir. Not sure what the if function is checking (plugin dir or site setting)

Also, I found this error in the error log being repeated a bunch of times. What does it mean?

[16-Jul-2011 23:42:28] PHP Fatal error: Call to undefined function add_action() in /blogdir/wp-content/plugins/wpmu-dev-facebook/wpmu-dev-facebook.php on line 31