Index: trunk/core/kernel/utility/debugger.php
===================================================================
diff -u -N -r4880 -r4885
--- trunk/core/kernel/utility/debugger.php	(.../debugger.php)	(revision 4880)
+++ trunk/core/kernel/utility/debugger.php	(.../debugger.php)	(revision 4885)
@@ -750,7 +750,13 @@
 						window.focus();
 					</script>
 				<?php
-					$memory_used = $debugger_start - $this->ProfilerTotals['error_handling'];
+					if (!isset($this->ProfilerTotals['error_handling'])) {
+						$memory_used = $debugger_start;
+						$this->ProfilerTotalCount['error_handling'] = 0;
+					}
+					else {
+						$memory_used = $debugger_start - $this->ProfilerTotals['error_handling'];
+					}
 
 					if ($returnResult) {
 						$ret = ob_get_contents();