A recent update of v29.2 broke spaces in file names for JSON based skins. We're now fixing this bug by an auto-update to v29.2.4. If you have built JSON based albums containing spaces using v29.2, let it auto-update to 29.2.4, then remake and re-upload affected galleries. You will probably need to clear your browser cache too in order for the browser to load the updated JSON files.
(JSON based albums are for instance albums made using Tiger, PhotoBlogger and Story)