Fancybox height problem when i use "preload:false" in Firefox

My fancybox would normally open to cover almost the entire screen. but when i do preload: false its height is too small.

How can i do fullscreen to fancybox with "preload:false"?

(I works chrome but isn't works Firefox)

First case: (there is no preload code)

$(document).ready(function () {

            var parent = "body";

            if ($(parent).find('li.iframePreload>.various:not(.notReloadOnClose)').length > 0) {
                $(parent).find("li.iframePreload>.various:not(.notReloadOnClose)").fancybox({
                    showCloseButton: false,
                    maxWidth: 1400,
                    maxHeight: 600,
                    fitToView: true,
                    width: '140%',
                    height: '80%',
                    type: 'iframe',
                    infobar: true,
                    buttons: ["close"],
                    autoSize: true,
                    closeClick: false,
                    openEffect: 'slideIn',
                    animationEffect: 'zoom-in-out',
                    closeEffect: 'slideIn',
                    title: '-',
                    onUpdate: function () {
                        FancyBoxOnUpdate();
                    },
                    afterLoad: function () {
                        FancyBoxAfterLoad(this);
                    },
                    helpers: {
                        locked: true,
                        overlay: { closeClick: false }
                    },
                    afterClose: function () {
                        location.reload();
                        return;
                    }
                });
            }

        });

second case: (there is preload code)

                    iframe: {
                        preload: false
                    }