I have tried and tried to control sidebars on single posts - without succes.
I am allways ending up with all 4 sidebars on single post - no matter what I try to do to control the sidebars - useing ATO - widget and sidebar - style and confiq sidebars.

Sidebar control works in page and category - but it's not working in single posts.

I like to have one category useing only left inner sidebar on singlepost.
And one category useing left and right sidebars on single post.

The only way is to exclude checkmark from "single posts" in ATO - but then all singleposts has the same sidebars. There most be a better way.

Can anybody help my out here - please.

I am running : Atahualpa 3.6.4 - amd latest wordpress

The theme allows you to set the sidebar display for the single post pages, but as you know it effects all single post pages. While you could use CSS like

body.uncategorized #left {display: none;}

this doesn't remove the space used by the sidebar and moves the middle area into the sidebar.

To do what you want, you will have to code a 'single.php' template and set the sidebars off based on the criteria you desire. There is a 'HOWTO: create a 'no sidebar' template (or 1, 2, 3 or 4 sidebar template)' thread in the gold forums tutorials you could use as a starting point.