seems to work!

fix.diff

diff --git a/classes/kohana/url.php b/classes/kohana/url.php
index e7e66bb..d95c7db 100644
--- a/classes/kohana/url.php
+++ b/classes/kohana/url.php
@@ -112,13 +112,18 @@ class Kohana_URL {
                if ( ! UTF8::is_ascii($path))
                {
                        // Encode all non-ASCII characters, as per RFC 1738
-                       $path = preg_replace('~([^/]+)~e', 'rawurlencode("$1")', $path);
+                       $path = preg_replace_callback('~([^/]+)~', 'URL::_rawurlencode_callback', $path);
                }
 
                // Concat the URL
                return URL::base($protocol, $index).$path;
        }
 
+       protected static function _rawurlencode_callback($matches)
+       {
+               return rawurlencode($matches[0]);
+       }
+
        /**
         * Merges the current GET parameters with an array of new or overloaded
         * parameters and returns the resulting query string.