Categories broken after WP 3.3.2 upgrade

My site is at untappedcities.com. After upgrading to 3.3.2, the categories on the homepage menu bar are now redirecting to random articles, showing a broken link, or redirecting to a URL that has dates added.

For example, untappedcities.com/category/urbanism forwards to https://untappedcities.com/2011/06/28/urbanism/

I tested out Twenty Eleven theme just to check, and the same issue occurs. I also deactivated the plugins.

Thanks