diff -uN matrix.module matrix.module
--- matrix.module	2011-01-13 13:02:09.000000000 +0200
+++ matrix.module	2011-01-17 19:22:35.000000000 +0200
@@ -54,12 +54,19 @@
         '#required' => TRUE,
         '#default_value' => isset($field["cols"]) ? $field["cols"] : '',
       );
+      $form['empty'] = array(
+          '#type' => 'textfield',
+          '#title' => t('Empty Values'),
+          '#default_value' => !empty($field['empty']) ? $field['empty'] : '',
+          '#description' => t('The value to place in Empty Fields. If nothing, leave this blank.'),
+          );
       return $form;
       
     case 'save':
       $values[] = 'rows';
       $values[] = 'cols';
       $values[] = 'size';
+      $values[] = 'empty';
       return $values;
   }
 }
@@ -90,6 +97,7 @@
       }
       $values['rows_header'] = $rows;
       $values['cols_header'] = $cols;
+      $values['empty'] = $field['empty'];
       $additions = array($field['field_name'] => $values);
       return $additions;
     case 'update':
@@ -255,6 +261,7 @@
 
   $processed_element['header'] = array('#value' => $header);
   $processed_element['first_col'] = array('#value' => $first_col);
+  $processed_element['empty'] = array('#value' => $field['empty']);
   return $processed_element;
 }
 
@@ -296,11 +303,12 @@
       ksort($row);
       foreach ($row as $cell_index => $cell_value) {
         if ($cell_value == '') {
-          $data[$row_index][$cell_index] = '-';
+          $data[$row_index][$cell_index] = $field_info['empty'];
         }
         else {
           $data[$row_index][$cell_index] = $cell_value;
           $show_row = $row_index;
+          $show_table = TRUE;
         }
       }
       $row_label =  '<b>'. array_shift($field_info['rows_header']) .'</b>';
@@ -313,7 +321,7 @@
     if ($row_count < count($header)) {
       for($i = $row_count; $i < count($header); $i++) {
         for ($j = 0; $j < count($data); $j++) {
-          $data[$j][$i] = '-';
+          $data[$j][$i] = $field_info['empty'];
         }
       }
     }
@@ -324,8 +332,12 @@
         $flushed_data[] = $row;
       }
     }
-    
-    return theme('table', $header, $flushed_data);
+    if ($show_table) {
+      return theme('table', $header, $flushed_data);
+    }
+    else {
+      return FALSE;
+    }
   }
 }