Index: wp-includes/option.php
===================================================================
--- wp-includes/option.php	(revision 24556)
+++ wp-includes/option.php	(working copy)
@@ -461,12 +461,13 @@
 				if ( get_option( $transient_timeout ) < time() ) {
 					delete_option( $transient_option  );
 					delete_option( $transient_timeout );
-					return false;
+					$value = false;
 				}
 			}
 		}
 
-		$value = get_option( $transient_option );
+		if ( !isset( $value ) )
+			$value = get_option( $transient_option );
 	}
 
 	return apply_filters( 'transient_' . $transient, $value );
@@ -1001,11 +1002,12 @@
 			if ( false !== $timeout && $timeout < time() ) {
 				delete_site_option( $transient_option  );
 				delete_site_option( $transient_timeout );
-				return false;
+				$value = false;
 			}
 		}
 
-		$value = get_site_option( $transient_option );
+		if ( !isset( $value ) )
+			$value = get_site_option( $transient_option );
 	}
 
 	return apply_filters( 'site_transient_' . $transient, $value );