next_posts_link, prev_posts_link not showing

My site is 49doors.com

I have a template for Category Index page, where the page will load all posts under a specific category. For example:
Category Index example

Another template for Category Archive shows similar results:
Archive example

I am able to have the next_posts_link and prev_posts_link show up on the Archive page, but not on the Category Index page.

This is what the code looks like for the Category Index:

<?php
/*
Template Name: Category Index
*/
get_header();
$pieces = explode("/", $_SERVER["REQUEST_URI"]);
array_pop($pieces);
$page_name = array_pop($pieces);
$idObj = get_category_by_slug( $page_name );
$thisCat = get_category( $idObj->term_id );
?>

		<div id="leftcontent">
			<div class="page-title" id="cat-index"><?php echo $thisCat->cat_name; ?></div>
			<!-- CMZ disable div class="contentheader"></div-->

			<?php
			global $more;
			$args = array( 'category' => $idObj->term_id, 'orderby' => 'post_date', 'order' => 'DESC', 'numberposts' => 10, 'paged' => $paged, );
			$myposts = get_posts( $args );
			$nr = 1;
			foreach( $myposts as $post ) :	setup_postdata($post);
			$more = 0;
			$custom = get_post_custom_values("featured_image");
			$category = get_the_category();
			$image = catch_that_image();
			$replace = 'images/posts/cropped';
			$cropped = preg_replace( '/images\/posts/', $replace, $image);
			?>

			<a href="<?php the_permalink(); ?>"><div class="excerpt-box2">
				<div class="content" >
					<div class="pic-frame">
						<?php if ( has_post_thumbnail() ) { ?>
							<div class="pic"><?php echo get_the_post_thumbnail();?></div>
						<?php } else { ?>
							<div class="pic" style="background-image:url(<?php echo $cropped ?>);background-size:cover;" ></div>
						<?php } ?>
					</div>
					<div class="post-meta">
						<span class="date"><?php the_time('l, F jS, Y') ?> /</span>
						<?php comments_popup_link('No Comments', '1 Comment', '% Comments', 'comments-link', ''); ?>
					</div>
					<div class="excerpt"><?php the_excerpt(); ?></div>
					<div class="square-sel"></div>
					<div class="cat-label"><?php echo $category[0]->cat_name; ?></div>
					<div class="title-banner">
						<a href="<?php the_permalink(); ?>"><div class="post-title"><?php get_the_category( ) ?><?php the_title(); ?></div></a>
					</div>
					<!-- CMZ disable div class="feedback-widget">
						<div class="comments"><?php comments_number( '', '1', '%' ); ?></div>
					</div --><!--end .feedback-widget-->
				</div><!--end .content-->
			</div><!--end .excerpt-box2--></a>

			<?php
			$nr++;
			endforeach; ?>

		<!--this is for the Older/Newer post navigation-->
		<?php include (TEMPLATEPATH . '/inc/nav.php' ); ?> 

		</div><!--end leftcontent-->

<?php get_sidebar(); ?>

<?php get_footer(); ?>

This code snippet is also used for the Archive page and works well:

<?php include (TEMPLATEPATH . '/inc/nav.php' ); ?>

points to:

<div class="navigation">
	<div class="next-posts"><?php next_posts_link('&laquo; Older Posts' ) ?></div>
	<div class="prev-posts"><?php previous_posts_link('Newer Posts &raquo;' ) ?></div>
</div>

Please any suggestions would be helpful – thank you.