Layered navigation block not working

[annashial]

Hi, I installed layered navigation block and I modified it so it is displayed horizontally in the centre of the page above the product list. It worked great when I made the changes. Then I added new products (around 90) and when I tried to filter using the layered navigation block it's not working. It does not filter, it does nothing. Also I noticed that I can't combine price filtering with other features filtering. I have read a lot of topics related to layered navigation block problems but I did not find a solution. Does anybody know what I have to do?

Thanks