problems with account creation

One thing I suspect you disabled pagination for that menu item, can you check that. Pagination must be enabled because infinite-scroll uses it to control loading.

Check under 'Options'

Pagination = Show
Pagination results = Show

pagination is: automatically
pagination results : show
exactly as in k2 categories that scroller works.
I can change automatically to show. It don't save this change. But as I said the other categories have the same option.
Sorry.
I try all the time differnet options and thoughts. I don't get it.
I am cloning a category that works and the new one don't.

I see all articles are loaded at once that's why I suspect it has something to do with that. Check category settings it has same parameters

Ivan, of course I checked many times the settings. That's why I say It is strange. I have the sames settings as the categories that scroller works. Or I give parental settings to my new category from your category and it doesn't work.
Maybe I should reinstall it. For me it is crucial to work with disqus comments too. And it seems impossible.

What happens if you create new category by copying our category and putting in it articles that are copy of our articles? (save an copy option)

The scroller plays. Notice that Ajax option in template is disabled!!!
So I have to copy categories... ok.
But even if Ajax is disabled scroller works and masonry works except page transitions.
I can't make disqus play. When Ajax is disabled normally disqus works.
And when Ajax is disabled scroller and masonry shouldn't work but the do!!!.
Anyway that was a step front. Scroller works.