This table isn’t custom code, it belongs to the normal code. I have made this table invisible in the search results with CSS code in my template stylesheet style.css.
It doesn’t matter whether I relate listings by tags or categories. But when I choose post excerpt=0, then the layout is ok. Something in the text of some listings cause the error.
I disabled the non GD plugins, but the problem was still there. By excluding the tab with related listings the problem is away. For now, this works for me.