Fourm horizontal scroll bar

Hi,

I noticed for the past few months a horizontal scroll bar is able to be scrolled on all pages on the forum like below..

Is there a way so the page sizes to the browser window so it doesn't scroll across ?

The browser is showing the whole page anyway so it's not like my browser is hiding any of the page so it needs to scroll across.

it is probably an unused side bar of the forum that is eating space. it's not there on the other pages.