Virtuemart Category Ovverides doesnt work as expected

[niosme]

When setting an ovveride for product from the category it doesnt always work and i dont know why.I added this to fix it

line:417
file:/public_html/components/com_virtuemart/views/productdetails/view.html.php
$layout = $this->category->category_product_layout!==$layout?$this->category->category_product_layout:$layout;