Ok, now it is in Swedish. I don't understand why this things happens on your configuration - it should actually work properly. You see the problem is that joomla first loads the SV translation and then the english one. And it should be the other way around - it should load the english translation, then overrride it with the SV. this way - all untranslated strings in your language will be at least in english and you won't wonder what the meaning of COM_HOTSPOTS_ADD_FORM should be.
But for some reason that I don't understand it doesn't work on your site as intended.
I've commented the code in components/com_hotspots/hotspots.php
//$jlang->load('com_hotspots', JPATH_SITE, 'en-GB', true);
//$jlang->load('com_hotspots', JPATH_SITE, $jlang->getDefault(), true);
//$jlang->load('com_hotspots', JPATH_SITE, null, true);
//$jlang->load('com_hotspots', JPATH_ADMINISTRATOR, 'en-GB', true);
//$jlang->load('com_hotspots', JPATH_ADMINISTRATOR, $jlang->getDefault(), true);
//$jlang->load('com_hotspots', JPATH_ADMINISTRATOR, null, true);
This code is responsible for the proper loading of the language files - as I said something strange is going on your site - maybe a language plugin???
Anyway - now only the sv file is loaded and you will see some untranslated strings. So please add them to your SV translation and give me the updated files and I'll put it in the next release.
Cheers,
Daniel