This is what I got if I use the 2nd option:
Warning [PHP]: Unknown(): URL file-access is disabled in the server configuration in file /home/mypage/public_html/html/class/xoopsblock.php(146) : eval()'d code line 7
Warning [PHP]: Unknown(http://www.mypage.com/html/test_special.php): failed to open stream: no suitable wrapper could be found in file /home/mypage/public_html/html/class/xoopsblock.php(146) : eval()'d code line 7
Warning [PHP]: (null)(): Failed opening 'http://www.mypage.com/html/test_special.php' for inclusion (include_path='.:/usr/lib/php:/usr/local/lib/php') in file /home/mypage/public_html/html/class/xoopsblock.php(146) : eval()'d code line 7

Not sure why my ISP disable it tough =).

I have also tried using absolute path, but still in vain.

Did you also call a function from the include?
I think include is working, just that you can't call the function from the include file.

Thanks for your reply m0nthy.

I did all what u said but problem still persist.

I wonder if include/require in custom block does not actually means including the file like normal php file?

Thanks.

I created a custom block with code:
require('\test_lib.php');
test();

the test_lib.php:
<?
function test()
{
echo "testing...";
}
?>

Amazingly the output complaining that test() is not defined. I dont' get it.

Another funny thing is that if I wrap my custom block code into its own php file for example wrapper.php, then in the custom block,i wrote:
require('wrapper.php');
then the code works.

The problem is that my ISP disallow the 2nd option.

Anyone has any clues?

Thanks.