Pagination shows same posts

Hello there,

as I was developing my blog layout with the plugin “Theme Test Drive”, I had some pagination issues on my template page, but I could solve them all. Now I rolled out my blog, but I got the same problem as before: the pagination function shows the same posts in every page.

Here is the code from my template page:

<?php get_header(); ?>

<div id="content">

	<?php if ( have_posts() ) : while ( have_posts() ) : the_post(); ?>
	<?php endwhile; else: endif; ?>

	<?php $temp = $wp_query; $wp_query= null;
	$wp_query = new WP_Query(); $wp_query->query('showposts=5' . '&paged='.$paged . '&category_name='.get_the_title());

	while ($wp_query->have_posts()) : $wp_query->the_post(); ?>

	<h2><a href="<?php the_permalink(); ?>"><?php the_title(); ?></a></h2>

	<div class="entry-byline">
		<span <?php hybrid_attr( 'entry-author' ); ?>><?php the_author_posts_link(); ?></span>
		<time <?php hybrid_attr( 'entry-published' ); ?>><?php echo get_the_date(); ?></time>
		<?php comments_popup_link( number_format_i18n( 0 ), number_format_i18n( 1 ), '%', 'comments-link', '' ); ?>
		<?php if ( function_exists( 'ev_post_views' ) ) ev_post_views( array( 'text' => '%s' ) ); ?>
		<?php edit_post_link(); ?>
	</div><!-- .entry-byline -->

	<?php
	global $more;
	$more = 0;
	?>

	<?php the_content( 'Mais...' ); ?> 	

	<div align="center"><img src="https://i2.wp.com/www.farofadechucrute.com/wp-content/uploads/2014/07/Separator2.png?resize=600%2C20" border="0"></div>

	<?php endwhile; ?>	

	<p align="center"><?php wpex_pagination(); ?></p>

</div>

<?php get_footer(); ?>

And here is the pagination functions in my functions.php:

// Numbered Pagination
if ( !function_exists( 'wpex_pagination' ) ) {

	function wpex_pagination() {

		$prev_arrow = is_rtl() ? '&rarr' : '<< Anterior';
		$next_arrow = is_rtl() ? '&larr' : 'Próximo >>';

		global $wp_query;
		$total = $wp_query->max_num_pages;
		$big = 999999999; // need an unlikely integer
		if( $total > 1 )  {
			 if( !$current_page = get_query_var('paged') )
				 $current_page = 1;
			 if( get_option('permalink_structure') ) {
				 $format = 'page/%#%/';
			 } else {
				 $format = '&paged=%#%';
			 }
			echo paginate_links(array(
				'base'			=> str_replace( $big, '%#%', esc_url( get_pagenum_link( $big ) ) ),
				'format'		=> $format,
				'current'		=> max( 1, get_query_var('paged') ),
				'total' 		=> $total,
				'mid_size'		=> 1,
				'type' 			=> 'plain',
				'prev_text'		=> $prev_arrow,
				'next_text'		=> $next_arrow,
				'before_page_number' 	=> '&nbsp',
				'after_page_number' 	=> '&nbsp',
			 ) );
		}
	}

}

What am I doing wrong? Can another function somewhere inside my child theme block the pagination function?

Thanks in advance

Cheers
Felipe