The error no longer occurs. It disappeared a couple of months after I posted here.
Thank you for checking it out anyway!

I'm sorry that it took us so long to respond to your question.
Looking at your site I could not recreate the issues you mentioned above. Do the errors still occur for you?

I have a few problems that, I believe, appeared ever since WordPress introduced the new feature where posts load automatically as you get to the bottom of the page (or in my case, when you have to click "Load more posts"):

1) The option to leave comments has vanished.

2) Previously left comments have vanished.

3) Post titles are no longer active links that you can click on.

These problems only appear on the following posts that load as you scroll further down the site. The ones that are on the front page are fine.
On my dashboard everything seems to be intact – the comments are there and the settings are as they should be.

The theme that I'm using is Tarski.

Link to my blog: http://elzarubule.wordpress.com/

Any help would be greatly appreciated!