Panels problem

I am using PRU8 for my personal website.
When i try to use PRU8 in combination with Panels 7.30 i can't add content in any panel region.

Below what i get instead:

[{"command":"settings","settings":{"basePath":"\/","pathPrefix":"","ajaxPageState":{"theme":"pru8","theme_token":"TWBpTd1tiZR1AAW2uEdfz1QQm7Ag-_rqaIQutBborg0","css":[]},"lightbox2":{"rtl":"0","file_path":"\/(\\w\\w\/)public:\/","default_image":"\/sites\/all\/modules\/lightbox2\/images\/brokenimage.jpg","border_size":12,"font_color":"fff","box_color":"000","top_position":"","overlay_opacity":"0.9","overlay_color":"000","disable_close_click":1,"resize_sequence":0,"resize_speed":400,"fade_in_speed":400,"slide_down_speed":600,"use_alt_layout":0,"disable_resize":0,"disable_zoom":false,"force_show_nav":0,"show_caption":1,"loop_items":1,"node_link_text":"","node_link_target":0,"image_count":"Foto !current van !total","video_count":"Video !current of !total","page_count":"Page !current of !total","lite_press_x_close":"Klik \u003ca href=\"#\" onclick=\"hideLightbox(); return FALSE;\"\u003e\u003ckbd\u003ex\u003c\/kbd\u003e\u003c\/a\u003e om te sluiten","download_link_text":"","enable_login":false,"enable_contact":false,"keys_close":"c x 27","keys_previous":"p 37","keys_next":"n 39","keys_zoom":"z","keys_play_pause":"32","display_image_size":"","image_node_sizes":"(\\.thumbnail)","trigger_lightbox_classes":"","trigger_lightbox_group_classes":"img.inline,img.flickr-photo-img,img.flickr-photoset-img,img.ImageFrame_image,img.ImageFrame_none,img.image-img_assist_custom,img.thumbnail, img.image-thumbnail","trigger_slideshow_classes":"","trigger_lightframe_classes":"","trigger_lightframe_group_classes":"","custom_class_handler":"lightbox","custom_trigger_classes":"img.test","disable_for_gallery_lists":1,"disable_for_acidfree_gallery_lists":true,"enable_acidfree_videos":true,"slideshow_interval":5000,"slideshow_automatic_start":true,"slideshow_automatic_exit":true,"show_play_pause":true,"pause_on_next_click":false,"pause_on_previous_click":true,"loop_slides":false,"iframe_width":600,"iframe_height":600,"iframe_border":1,"enable_video":0}},"merge":true},{"command":"modal_display","title":"Add content to Bovenaan","output":"\u003cdiv class=\"panels-add-content-modal\"\u003e\u003cdiv class=\"panels-section-column panels-section-column-categories\"\u003e\u003cdiv class=\"inside\"\u003e\u003cdiv class=\"panels-categories-box\"\u003e\u003ca href=\"\/panels\/ajax\/editor\/select-content\/4\/top\/activiteit\" class=\"use-ajax panels-modal-add-category\" title=\"\"\u003eActiviteit\u003c\/a\u003e\u003ca href=\"\/panels\/ajax\/editor\/select-content\/4\/top\/custom-blocks\" class=\"use-ajax panels-modal-add-category\" title=\"\"\u003eCustom blocks\u003c\/a\u003e\u003ca href=\"\/panels\/ajax\/editor\/select-content\/4\/top\/diverse\" class=\"use-ajax panels-modal-add-category\" title=\"\"\u003eDiverse\u003c\/a\u003e\u003ca href=\"\/panels\/ajax\/editor\/select-content\/4\/top\/menu-s\" class=\"use-ajax panels-modal-add-category\" title=\"\"\u003eMenu's\u003c\/a\u003e\u003ca href=\"\/panels\/ajax\/editor\/select-content\/4\/top\/node\" class=\"use-ajax panels-modal-add-category\" title=\"\"\u003eNode\u003c\/a\u003e\u003ca href=\"\/panels\/ajax\/editor\/select-content\/4\/top\/node--tokens-\" class=\"use-ajax panels-modal-add-category\" title=\"\"\u003eNode (tokens)\u003c\/a\u003e\u003ca href=\"\/panels\/ajax\/editor\/select-content\/4\/top\/pagina-elementen\" class=\"use-ajax panels-modal-add-category\" title=\"\"\u003ePagina-elementen\u003c\/a\u003e\u003ca href=\"\/panels\/ajax\/editor\/select-content\/4\/top\/widgets\" class=\"use-ajax panels-modal-add-category\" title=\"\"\u003eWidgets\u003c\/a\u003e\u003c\/div\u003e\u003cdiv class=\"content-type-button clearfix\"\u003e\u003ca href=\"\/panels\/ajax\/editor\/add-pane\/4\/top\/custom\/custom\" class=\"use-ajax panels-modal-add-config\" title=\"Create a completely custom piece of HTML content.\"\u003e\u003cimg src=\"http:\/\/www.molema-smit.nl\/sites\/all\/modules\/ctools\/images\/no-icon.png\" alt=\"\" \/\u003e\u003c\/a\u003e\u003cdiv\u003e\u003ca href=\"\/panels\/ajax\/editor\/add-pane\/4\/top\/custom\/custom\" class=\"use-ajax panels-modal-add-config\" title=\"Create a completely custom piece of HTML content.\"\u003eNew custom content\u003c\/a\u003e\u003c\/div\u003e\u003c\/div\u003e\u003cdiv class=\"content-type-button clearfix\"\u003e\u003ca href=\"\/panels\/ajax\/editor\/add-pane\/4\/top\/node\/node\" class=\"use-ajax panels-modal-add-config\" title=\"Een node van de site toevoegen als inhoud.\"\u003e\u003cimg src=\"http:\/\/www.molema-smit.nl\/sites\/all\/modules\/ctools\/plugins\/content_types\/node\/icon_node.png\" alt=\"\" \/\u003e\u003c\/a\u003e\u003cdiv\u003e\u003ca href=\"\/panels\/ajax\/editor\/add-pane\/4\/top\/node\/node\" class=\"use-ajax panels-modal-add-config\" title=\"Een node van de site toevoegen als inhoud.\"\u003eBestaande node\u003c\/a\u003e\u003c\/div\u003e\u003c\/div\u003e\u003c\/div\u003e\u003c\/div\u003e\u003cdiv class=\"panels-categories-description\"\u003eContent options are divided by category. Please select a category from the left to proceed.\u003c\/div\u003e\u003c\/div\u003e"}]

Using a standard drupal 7 theme everything works just fine.
On Drupal.org i found a possible solution:

"One thing I've noticed is that themes that do not properly contain $closure in their page.tpl.php file are causing things to break by not containing some necessary javascript. This is one thing to check".

Is it possible to look in to this problem, it seems to be theme related.

Fouch