XML sitemap SEO by yoast, can't find other language sitemap

http://wpml.org/forums/topic/xml-sitemap-seo-by-yoast-cant-find-other-language/#post-347153

http://cyberchimps.com/forum-topic/responsive-pro-seo-yoast-xml-sitemap-wpml/

Can you please let me know if you can give me advise why the SEO by yoast sitemap cannot find the other language’s site in english and traditional Chinese? Is there a set up that I miss in the theme options or seo setting set up? Thanks so much.