The current Joomla 3 versions of Joomla are based on Twitter Bootstrap 2.3.2 unfortunately not all templates have this on board. So you will run in troubles becuae our templates (within the component) are not showing up as it should be.
Pretty much of the templates installed in Joomla don't have Twitter Bootstrap integration, so you have to make changes to the CSS (which is pretty much work) But you can also integratie it in your template. http://www.inmotionhosting.com/support/edu/joomla-3/create-template/add-bootstrap
Or another solution is using this plugin:
It will install Twitter bootstrap and loads the needed CSS files for you in your Joomla template. You will see that everything is OK after publishing the plugin.