Sidebars go to the bottom of the page.

Some (non-shrinking) content such as an image or a form in a sidebar is probably too big to fit in at the given screen size. Try increasing the width of that sidebar on the options page, additionally you may have to increase the “min-width” value on the options page.

…and if you are sincere about wanting help with display issues, next time, please provide a link to your blog.

Thank you very much for your kind advices.
My blog is:
https://www.shakespeare-w.com/blog/

I have downloaded the latest version of 2.21 and uploaded it. I was using v.2.01 which I downloaded here. Then, it seems that it fixed all problems which I had, expect the post numbers of archive are still wrong.

Thank you very much!

my blog has the same problem, i am already using version 2.2. It depends which browser to open, if IE the sidebar will down bottom even after i adjusted the width. But if I use Chrome then the problem goes away. Please help.

My site is https://traderwork.com/

https://validator.w3.org/check?verbose=1&uri=http%3A%2F%2Fwww.traderwork.com%2F

After agonizing over the display in the much hated IE, I made my sidebar slightly bigger in the theme setting and it fixed it.
Thank you BytesForAll

The next version is a complete rewrite and will not have the dropping sidebar issue anymore.

Regarding the W3C link of Whooami: The Atahualpa theme is and always was valid XHTML transitional: https://validator.w3.org/check?uri=http%3A%2F%2Fwww.bytesforall.com%2Fwordpress-test%2F9%2F&charset=%28detect+automatically%29&doctype=Inline&group=0

The site in question may have had errors at the time Whooami posted the link though, probably caused by content or plugins. That can happen quite easily and is not always theme related. (Note: If you check Whooami’s W3C link: the site’s using another theme now)