Problem occur with HTML Validator for same wepage but different URL input method if using zh-hk as primary language

Hello!

I am validating the following webpage
http://konami-asia.com/cn-t/index.php -> the validation result: valid

if I just type only "http://konami-asia.com/cn-t/" -> the validation result
is not valid for the following character:

---------------------------------------------------------------------------------------------------------------------------------------------------------------------
Error  Line 159, Column 292: End of file seen and there were open elements.
---------------------------------------------------------------------------------------------------------------------------------------------------------------------

Actually the url http://konami-asia.com/cn-t/ -> is reading
http://konami-asia.com/cn-t/index.php

Why there will have such difference?

Also, If I change my nature code from zh-hk to zh-tw, it result in no
problem too.
I wonder what is the problem of my page.

There are 2 more pages running at same structure:
http://konami-asia.com/cn-s/ (nature encode:zh-cn) -> the validation result:
valid
http://konami-asia.com/en/ (nature encode:en) -> the validation result:
valid

The page itself display unicode because there are Japanese, English +
Chinese Traditional or Chinese Simplified character.

Thanks!

Best regards,
Sorcerer