Index: performance/performance.install
===================================================================
--- performance/performance.install	(revision 6286aff51effe48db7667d04bd4744e40a3adc6d)
+++ performance/performance.install	(revision )
@@ -134,10 +134,15 @@
 function performance_update_7001() {
   $int_field = array('type' => 'int', 'not null' => TRUE, 'default' => 0, 'disp-width' => '11');
 
+  if (db_field_exists('performance_summary', 'millisecs_max')) {
-  db_change_field('performance_summary', 'millisecs_max', 'ms_max', $int_field);
+    db_change_field('performance_summary', 'millisecs_max', 'ms_max', $int_field);
+  }
+  if (db_field_exists('performance_summary', 'millisecs_avg')) {
-  db_change_field('performance_summary', 'millisecs_avg', 'ms_avg', $int_field);
+    db_change_field('performance_summary', 'millisecs_avg', 'ms_avg', $int_field);
+  }
+  if (db_field_exists('performance_detail', 'millisecs')) {
-  db_change_field('performance_detail',  'millisecs',     'ms',     $int_field);
+    db_change_field('performance_detail', 'millisecs', 'ms', $int_field);
-
+  }
   // We don't have a cache update method, so it's better to clear it
   if (function_exists('apc_fetch')) {
     apc_clear_cache('user');