Issue with Google-Style Pagination

Hello all,

I am using a function to show Google-style pagination (<<1,2,3>>) instead of the standard “Previous/Next” using a script I found online. It’s working great except I am getting a strange error every once-in-awhile when running it. Here’s the PHP which is pasted into function.php:

<?php function wp_pagenaviNew($before = '', $after = '', $prelabel = '', $nxtlabel = '', $pages_to_show = 5, $always_show = false)
{
	global $request, $posts_per_page, $wpdb, $paged;
	   if(empty($prelabel)) { $prelabel = '<strong><<</strong>';
	} if(empty($nxtlabel)) {

$nxtlabel = '<strong>>></strong>';
	} $half_pages_to_show = round($pages_to_show/2);
	   if (!is_single()) {
	   if(!is_category()) {
preg_match('#FROM\s(.*)\sORDER BY#siU', $request, $matches); } else {
preg_match('#FROM\s(.*)\sGROUP BY#siU', $request, $matches); }

$fromwhere = $matches[1];
$numposts = $wpdb->get_var("SELECT COUNT(DISTINCT ID) FROM $fromwhere");
$max_page = ceil($numposts /$posts_per_page);
if(empty($paged)) {
$paged = 1;
}

if($max_page > 1 || $always_show) {
echo "$before <div class='Nav'>Pages ($max_page): "; if ($paged >= ($pages_to_show-1)) {
echo '<a href="'.get_pagenum_link().'"><< First</a>  '; }
	previous_posts_link($prelabel);
for($i = $paged - $half_pages_to_show; $i <= $paged + $half_pages_to_show; $i++) { if ($i >= 1 && $i <= $max_page) { if($i == $paged) {
echo "<strong class='on'>$i</strong>";
} else {
echo ' <a href="'.get_pagenum_link($i).'">'.$i.'</a> '; }
}
}
next_posts_link($nxtlabel, $max_page);
if (($paged+$half_pages_to_show) < ($max_page)) {
echo '  <a href="'.get_pagenum_link($max_page).'">Last >></a>'; }
echo "</div> $after";
}
}
}
?>

The error involves something about writing to the header and includes an error to line 850 of pluggable.php which seems to have something to do with the location URL. But, I can’t seem to get the error to happen consistently and it just started occurring when I put this script in. Anyone know what is going on or if it is something with pluggable.php? Thanks!