Multiple forms

I am running mutiple forms on a single page, they all submit and then force dowenload a pdf.

When I had a single form it was working, then I added additional forms and the dowenload stopped working.

Just as an example since you can't see the php code

add_filter("gform_validation_message_2", "change_message", 99, 2);
add_filter("gform_ajax_spinner_url_2", "spinner_url", 10, 2);

add_action("gform_post_submission_2", "post_submission_2", 99, 2);

function change_message($message, $form){
    return '';
}

function spinner_url($image_src, $form){
    return "";
}

function post_submission_2($lead, $form) {

	$data = '/pdf/DesignGuide.pdf';
	$name = 'MegaDome-Design-Guide.pdf';

	force_download($name, $data); 

}

Everything works as expected, except now for some reason the pdf if around 20kb, which is just an empty corrupt pdf.

I haven't changed anyhting else except the forms, so I'm not sure whast it could be.

any thoughts?