Sort by price Error

[enigjinaj]

Hello, 
I'm using PS 1.6.1.5. Most of my products have attributes. I've noticed that when I list category products sorted by price (lowest first), the pagination fails when moving between pages. Example the product of the first page is 40$ and the first product in my second page is 20$. I think the sorter does sort by base price, no taking into account reduction prices.

I've been searching so long to find a solution but i can't find anything. Does anyone how to fix it?

Thank you in advance,

Florida