Index: includes/theme.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/theme.inc,v
retrieving revision 1.330
diff -u -r1.330 theme.inc
--- includes/theme.inc	10 Dec 2006 09:54:32 -0000	1.330
+++ includes/theme.inc	13 Dec 2006 22:05:47 -0000
@@ -849,10 +849,12 @@
  *   A string containing the block output.
  */
 function theme_block($block) {
-  $output  = "<div class=\"block block-$block->module\" id=\"block-$block->module-$block->delta\">\n";
-  $output .= " <h2 class=\"title\">$block->subject</h2>\n";
-  $output .= " <div class=\"content\">$block->content</div>\n";
-  $output .= "</div>\n";
+  $output  = '<div class="block block-'. $block->module .'" id="block-'. $block->module .'-'. $block->delta .'">';
+  if (!isset($block->subject)) {
+    $output .= '<h2 class="title">'. $block->subject .'</h2>';
+  }
+  $output .= '<div class="content">'. $block->content .'</div>';
+  $output .= '</div>';
   return $output;
 }