=== modified file 'modules/system/system.install'
--- modules/system/system.install	2007-09-22 22:18:52 +0000
+++ modules/system/system.install	2007-09-22 22:41:45 +0000
@@ -26,8 +26,8 @@
     'value' => $software,
   );
   // Use server info string, if present.
-  if ($software && preg_match('![0-9]!', $software)) {
-    list($server, $version) = split('[ /]', $software);
+  list($server, $version) = split('[ /]', $software);
+  if ($software && preg_match('![0-9]!', $software)) {    
     switch ($server) {
       case 'Apache':
         if (version_compare($version, DRUPAL_MINIMUM_APACHE) < 0) {
@@ -43,9 +43,11 @@
     }
   }
   else {
-    $requirements['webserver']['value'] = $software ? $software : $t('Unknown');
-    $requirements['webserver']['description'] = $t('Unable to determine your web server type and version. Drupal might not work properly.');
-    $requirements['webserver']['severity'] = REQUIREMENT_WARNING;
+    if (!in_array($server, array('lighttpd', 'nginx'))) {
+      $requirements['webserver']['value'] = $software ? $software : $t('Unknown');
+      $requirements['webserver']['description'] = $t('Unable to determine your web server type and version. Drupal might not work properly.');
+      $requirements['webserver']['severity'] = REQUIREMENT_WARNING;
+    }
   }
 
   // Test PHP version