PROBLEM!!! product navigation arrows doesnt work

[vmfuo]

Hi, I can not get the product navigation arrows to appear on the top right of the product details pages
I use virtuemart 3.0.6 and joomla 3.4.0. latest version but the problem is still there. I do have Configuration -> Shopfront ->"Show the product navigation?" ticked, After some tests i realize that the 'next' arrow shows only the first two products of current category and the 'previous' arrow shows only the two last products of the category ('middle' products never displayed). 

[Milbo]

check your default ordering in the vm config,