--- wp-includes/functions.php.orig	Mon Aug 03 01:18:21 2009
+++ wp-includes/functions.php	Mon Aug 03 01:14:51 2009
@@ -86,15 +86,18 @@
 function date_i18n( $dateformatstring, $unixtimestamp = false, $gmt = false ) {
 	global $wp_locale;
 	$i = $unixtimestamp;
-	// Sanity check for PHP 5.1.0-
-	if ( false === $i || intval($i) < 0 ) {
-		if ( ! $gmt )
-			$i = current_time( 'timestamp' );
-		else
-			$i = time();
-		// we should not let date() interfere with our
-		// specially computed timestamp
-		$gmt = true;
+
+	if (version_compare( '5.1.0', phpversion(), '>=' )) {
+		// Sanity check for PHP 5.1.0-
+		if ( false === $i || intval($i) < 0 ) {
+			if ( ! $gmt )
+				$i = current_time( 'timestamp' );
+			else
+				$i = time();
+			// we should not let date() interfere with our
+			// specially computed timestamp
+			$gmt = true;
+		}
 	}
 
 	// store original value for language with untypical grammars