Sort by category doesn't work on Main page

In all browsers (IE 7 & 8, FF3, Chrome, Safari 3), if you're on the home page of a groupsite, in the "Recent Blog Posts" module, if you click on a category, nothing happens.  It should, I assume, show a page with all the blog posts under that category.

If you're in "Featured Blog Post" mode, clicking on a category link will result in a 404 error (URL was http://******.collectivex.com/content?category=New+Orleans;  stars=groupsite name)

Works fine when you go to the Group Blog page and do it from there.