Shortcodes not working

Question

I have WordPress 3.2.1 and I have created a personal shortcode, everything works fine until I change the Permalink Settings from Default to Custom Structure. The shortcodes stop to work permanently, instead I turn back to Default setting.

Hello, I'm [birthday year="1975-03-25"] years old.

I've added add_shortcode function in my theme's functions.php.
If I add the new shortcode to the original WordPress theme Twenty Eleven in the functions.php file, it works fine!

my functions.php file:

function short_birthday ($date) {
    list($Y,$m,$d) = explode("-", $date['year']);
    return( date("md") < $m.$d ? date("Y")-$Y-1 : date("Y")-$Y );
}
add_shortcode('birthday', 'short_birthday');

this is the only thing I've added to functions.php.

How my theme can block the shortcodes? It's the only thing I've did.
Can I do something to fix it?

Answer 1

This is how your shortcode should be set up:

function short_birthday( $atts, $content = NULL ) {
    extract( shortcode_atts( array(
        'year' => 'default value'
    ), $atts ) );

    list( $Y, $m, $d ) = explode( "-", $year );
    $data = date( "md" ) < $m.$d ? date( "Y" )-$Y-1 : date( "Y" )-$Y;
    return $data;
}
add_shortcode( 'birthday', 'short_birthday' );

Answer 2

Have you tried to use the html view to paste the shortcode ? Sometimes html tags are copied when you copy the shortcode and makes it behave like this.