If I visit your first link and look at the response, I get a 500 Internal Server Error when trying to get the following resource: http://designportugal.net/wp-content/themes/dt-nimble/timthumb.php?src=/wp-content/uploads/2012/11/drpedrocoelho.png&zc=1&w=30&h=30 so my guess is that your problem is with the timthumb plugin. Try disabling the plugin and see if your error goes away.
