Index: wp-includes/script-loader.php
===================================================================
--- wp-includes/script-loader.php	(revision 23060)
+++ wp-includes/script-loader.php	(working copy)
@@ -689,8 +689,8 @@
 	if ( $zip && defined('ENFORCE_GZIP') && ENFORCE_GZIP )
 		$zip = 'gzip';
 
-	if ( !empty($wp_scripts->concat) ) {
-
+	$concat = trim( $wp_scripts->concat, ', ' );
+	if ( $concat ) {
 		if ( !empty($wp_scripts->print_code) ) {
 			echo "\n<script type='text/javascript'>\n";
 			echo "/* <![CDATA[ */\n"; // not needed in HTML 5
@@ -699,8 +699,25 @@
 			echo "</script>\n";
 		}
 
-		$src = $wp_scripts->base_url . "/wp-admin/load-scripts.php?c={$zip}&load=" . trim($wp_scripts->concat, ', ') . '&ver=' . $wp_scripts->default_version;
-		echo "<script type='text/javascript' src='" . esc_attr($src) . "'></script>\n";
+		if ( strlen( $concat ) <= 512 ) {
+			$src = $wp_scripts->base_url . "/wp-admin/load-scripts.php?c={$zip}&load=" . $concat . '&ver=' . $wp_scripts->default_version;
+			echo "<script type='text/javascript' src='" . esc_attr($src) . "'></script>\n";
+		} else {
+			$scripts = explode( ',', $concat );
+			$concat = '';
+			foreach ( $scripts as $script ) {
+				if ( strlen( $concat ) + strlen( $script ) > 513 ) {
+					$src = $wp_scripts->base_url . "/wp-admin/load-scripts.php?c={$zip}&load=" . trim( $concat, ',' ) . '&ver=' . $wp_scripts->default_version;
+					echo "<script type='text/javascript' src='" . esc_attr($src) . "'></script>\n";
+					$concat = '';
+				}
+				$concat .= ',' . $script;
+			}
+			if ( $concat ) {
+				$src = $wp_scripts->base_url . "/wp-admin/load-scripts.php?c={$zip}&load=" . trim( $concat, ',' ) . '&ver=' . $wp_scripts->default_version;
+				echo "<script type='text/javascript' src='" . esc_attr($src) . "'></script>\n";
+			}
+		}
 	}
 
 	if ( !empty($wp_scripts->print_html) )