If I am pressing the add to cart button, browser redirects me to new page where
ajax callback object is exposed.

{"form_id":"uc_product_add_to_cart_form_1","content":"
4x<\/td> aaa<\/a><\/td> $444.00<\/td><\/tr><\/tbody><\/table><\/div>
4 Items<\/td> Total:<\/strong> $444.00<\/td><\/tr>
(View cart<\/a>) (Checkout<\/a>)<\/td><\/tr><\/tbody><\/table>"}

I have all modules updated to last stable and it is fresh install.
Clean urls are not enabled.

best regards

Joel