when i click page '2', it goes back to home page

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$siteurl = get_option('siteurl');
	global $post, $paged;
	$data = '';
	$temp = $wp_query;
  	$my_query2= null;
	$paged = (get_query_var('paged')) ? get_query_var('paged') : 1;
	$my_query2 = new WP_Query( array( 'post_type' => 'portfolio',
									 'paged' => $paged,
									 'posts_per_page' => '10',
								   )
							);
	while ( $my_query2->have_posts() ) : $my_query2->the_post();
		$image = wp_get_attachment_image_src( get_post_thumbnail_id( $post->ID ), 'medium' );
		$content = excerpt($post->post_content);
		$data = '
				<div class="grid_7 ports">
					<div class="">
						<img src="'.$image[0].'" style="border:solid 1px #ccc">
						<p class="port-title">'.$post->post_title.'</p>
						<p class="port-content">
						'.$content.'

						<a>ID.'" class="viewmore">view more..</a>
						</p>

					</div>
				</div>
				';
		echo $data;
	endwhile;
	wp_pagenavi( array( 'query' => $my_query2 ) );
	wp_reset_postdata();

http://wordpress.org/extend/plugins/wp-pagenavi/