Different numbers of posts on different pages

Hi,

I’m currently building a theme where, on the first page of the theme, I’m showing 3 posts, then on page 2 or higher, I want to show 12 posts.

I use the following code to grab the page number and change my loop settings (as the styles are very different from frontpage to page 2).

<?php if ( !is_single() && $paged > 1 )	{ ?> <!-- This is for pages after the frontpage, so page numbers > 1. -->
			<div id="maincontent2">
        		<div id="loopheader2">
            		<?php echo previous_posts_link( __( '<< Newer posts' ) ); ?>
					<div id=nextpost>
            			<?php next_posts_link( __( 'Older posts >>') ); ?>
            		</div> <!--id="nextpost" -->
				</div> <!--id="loopheader" -->
				<?php if (have_posts()) : ?>
				<?php while (have_posts()) : the_post(); ?>
					<div id="older">
						<?php attachment_image_or_postthumb('thumbnail'); ?>
						<br />
						<div style="text-indent:10px;">
						<a href="<?php the_permalink() ?>" rel="bookmark" title="Permanent Link to <?php the_title(); ?>"><?php the_title(); ?></a>
						</div> <!-- style="text-indent:10px;" -->
					</div> <!--id="older" -->
				<?php endwhile; ?>
				<?php endif; ?>
				<br />
			</div> <!-- id="maincontent" -->
<!-- This is where the if switches to the first page -->
		<?php } else { ?>
			<div id="maincontent">
        		<div id="loopheader">
   					<? echo "Latest Posts"; ?>
					<div id=nextpost>
            			<?php next_posts_link( __( 'Older posts >>',0 ) ); ?>
            		</div><!--id="nextpost" -->
				</div> <!--id="loopheader" -->
			<?php if (have_posts()) : $count = 0; ?>
			<?php while (have_posts()) : the_post(); ?>
				<div <?php if($counter==0) { echo 'id="first"'; $counter++; } else { echo 'id="rest"'; $counter++; } ?>>
					<?php attachment_image_or_postthumb('thumbnail'); ?>
					<br />
					<div style="text-indent:10px;">
					<a href="<?php the_permalink() ?>" rel="bookmark" title="Permanent Link to <?php the_title(); ?>"><?php the_title(); ?></a>
					</div> <!-- style="text-indent:10px;" -->
				</div> <!--id="older" -->
			<?php endwhile; ?>
			<?php endif; ?>

I’ve tried using the Custom Post Limits plugin by coffee2code but when I do the next posts link disappears on page 2, despite there being more than 15 posts.

I’ve tried using query_posts and showposts but when I get to page 2 its starts on post 13.

Can anyone suggest a solution?