Fixing weird margin in IE8 for my custom theme

Hi guys. I'm soon to launch a site with a custom responsive theme that conditionally loads a separate stylesheet for IE8..

I don't have IE8 to test on but I've been sent the attached screenshots which show a =n odd margin on the left.

I've routed through the stylesheet but can't seem to fix it. Can anyone help?

This is the site:
Check it on Firefox or Chrome to see how it should look!

Many thanks