Webmaster tools> html suggestions >Missing title tags

I submitted my first WP site to google on 29/1/12 and it has been indexed. However, in webmaster tools>HTML suggestions it says that there are missing title tags on the on the / page. The site is http://www.letsgoyoga.com and assuming that the home page is the problem, I have checked the source code and can see a title tag containing the keywords ‘Yoga in Twickenham’. I need to understand the impact of this message – could it be accounting for the site’s bad page rank and serp position(when searching for the keywords)- and how to fix it. Also I have noticed that when I google letsgoyoga the home page is not in the serp.

Any help would be gratefully received. Apologies if I am missing something basic.