Index: modules/system/system.install
===================================================================
RCS file: /cvs/drupal/drupal/modules/system/system.install,v
retrieving revision 1.308
diff -u -r1.308 system.install
--- modules/system/system.install	18 Feb 2009 15:19:56 -0000	1.308
+++ modules/system/system.install	25 Feb 2009 10:04:13 -0000
@@ -65,10 +65,10 @@
   $memory_limit = ini_get('memory_limit');
   $requirements['php_memory_limit'] = array(
     'title' => $t('PHP memory limit'),
-    'value' => $memory_limit,
+    'value' => $memory_limit == -1 ? t('-1 (Unlimited)') : $memory_limit,
   );
 
-  if ($memory_limit && parse_size($memory_limit) < parse_size(DRUPAL_MINIMUM_PHP_MEMORY_LIMIT)) {
+  if ($memory_limit && $memory_limit != -1 && parse_size($memory_limit) < parse_size(DRUPAL_MINIMUM_PHP_MEMORY_LIMIT)) {
     $description = '';
     if ($phase == 'install') {
       $description = $t('Consider increasing your PHP memory limit to %memory_minimum_limit to help prevent errors in the installation process.', array('%memory_minimum_limit' => DRUPAL_MINIMUM_PHP_MEMORY_LIMIT));