Index: wp-includes/functions.php
===================================================================
--- wp-includes/functions.php	(revision 5904)
+++ wp-includes/functions.php	(working copy)
@@ -286,9 +286,6 @@
 	$safe_option_name = $wpdb->escape($option_name);
 	$newvalue = sanitize_option($option_name, $newvalue);
 
-	if ( is_string($newvalue) )
-		$newvalue = trim($newvalue);
-
 	// If the new and old values are the same, no need to update.
 	$oldvalue = get_option($safe_option_name);
 	if ( $newvalue === $oldvalue ) {