Can not see post when e-commerce is activated

I am helping out a client of mine on his website and I am having the hardest time trying to figure out what the issue is. Whenever I activate WP-e-commerce plugin his blog post will not display.

If you click on the continue reading on his site you get page not found
http://thinkingateverydesk.org/blog/

I played around with a lot of different things and still doesn’t seem to work. Please help me out.