Fatal error when displaying product

[intense]

Hi, I'm developing a programm which will parse XML files and add products from that file (or update them) into prestashop.
If I will select category from the menu and some product after that from the list, it will normaly display it so everythink is OK.
But now, if I select some product from the "New products" or "Featured products" section or by clicking hotlink it will throw me a Fatal error but URL's are same.
I found that I can enable backtrace so here is it: http://pastebin.com/RKYLBtUY
And here is a screenshot that explain what I mean: http://www.upnito.sk/0/jjee2szpmdzs2qyzyxzkawedm2e965ge.png
I cannot provide source code of the parser because it's closed source but I can provide mysql queries which I'm using to import products into prestashop. Here they are:
insert into ps_product (id_manufacturer,quantity,price,wholesale_price,reference,supplier_reference,active,date_add,date_upd,id_tax) values (?,?,?,?,?,?,1,now(),now(),0) <-inserting product
select id_product from ps_product where reference=? and supplier_reference=? <-getting product id
insert into ps_product_lang (id_product,id_lang,description,link_rewrite,name) values (?,?,?,?,?) <-inserting description, name and link rewrite
insert into ps_category_product (id_category,id_product) values (1,?) <--- inserting into default category
insert into ps_category_product (id_category,id_product) values (?,?) <--- inserting into category

Have I missed somethink or where is problem? (I don't know php so I don't understand that backtrace very well)
Sorry for my English and thanks for help. :-)

[intense]

Problem solved. I'm stupid, I forget to insert data into id_category_default column :-)