diff --git a/cake/libs/i18n.php b/cake/libs/i18n.php
index <HASH>..<HASH> 100644
--- a/cake/libs/i18n.php
+++ b/cake/libs/i18n.php
@@ -321,8 +321,10 @@ class I18n extends Object {
 			$this->__domains[$domain][$this->__lang][$this->category] = array();
 			return $domain;
 		}
-
-		if ($head = $this->__domains[$domain][$this->__lang][$this->category][""]) {
+		
+		if (isset($this->__domains[$domain][$this->__lang][$this->category][""])) {
+			$head = $this->__domains[$domain][$this->__lang][$this->category][""];
+			
 			foreach (explode("\n", $head) as $line) {
 				$header = strtok($line,":");
 				$line = trim(strtok("\n"));
Fixing notice errors caused by accessing headers in po files that
don't exist. Fixes #<I>