I'm new to this and I may be missing something basic; I've tried searching on it but found nothing.

How can I get the sidebars to show on the Posts page?

As it is, it doesn't matter whether I set 'Front page displays' to Posts or a static page with a designated posts page, the sidebars disappear. They are working fine everywhere else and if I change the designated Posts page to something else, then they reappear on the page I first had designated.

The sidebars can be turned on/off for all single post pages but not for specific single post pages in case you were trying that

No, I want the sidebars to appear on all pages including the Posts page.

I'm working with the default settings for the theme, is there something I need to do to "turn on" the sidebars specifically n the Posts page?

I would need to see a URL with the error. I just tried and I don't have this issue.

I don't know what was going on

I had this problem with my site on a local pc (Windows XP). I uploaded it to my main server (Windows 2003) and it's working fine.

I haven't had a chance to explore it and probably won't.

Atahualpa is an excellent theme but does far more than I'll ever need as I want a minimalist appearance and something lighter will do that for me.