Checkout page breaking sidebar width

On my checkout pages my sidebar gets reduced from what it should be, breaking my layout a little in places.

I have attached a screenshot. The top section shows the checkout page with the width of the sidebar smaller than it should be, the bottom section shows the product list page with the sidebar the correct width.

I cannot figure out where to change this.

In the css I have looked at the

#hikashop_checkout_page

#hikashop_checkout_page div.hikashop_cart_bar{
	text-align:center;
    width: inherit;
}


#hikashop_checkout_page div.hikashop_cart_bar{
	text-align:center;
    width: auto;
}

#hikashop_checkout_page div.hikashop_cart_bar{
	text-align:center;
    width: 100%;
}

#hikashop_checkout_page div.hikashop_cart_bar{
	text-align:center;
    width: 90%;
}

Think I have figured this one out by myself now.

I found in the css;

/* checkout address layout */
.hikashop_checkout_address{
	clear:both;
	width:700px;
	margin:auto;
}

Thanks - I see that several elements have widths defined - would it not make more sense giving them percentages so they fit more peoples templates?

Just out of interest - why don't percentages work in some cases?

Going through my checkout pages now changing the widths - it's easy enough but would be nice for the pages to just fit to the container no matter what size I have it set to, as it does with the category/product views.

Thanks again
Simon