border-bottom:1px solid #BCD2E6;
font: bold 11px/1.5em Tahoma;
Define a width that accomodates the accumulated width of the tabs, and a height, and you will probably have to 'position:relative; ' this, or center it. However it looks best.
This should force the tabs to remain horizontal (even though the "display:inline;" for the <li> should take care of that..).
I might suggest, from a SEO stance, that the <title></title> be changed from:
<title>== Welcome to Continental Products - Industrial and Construction Adhesives ==</title>
<title>Continental Products - Industrial and Construction Adhesives ==</title>
so that the page is indexed properly by the first-letter of the corporation name. Otherwise, the site gets indexed by either "==" or "Welcome~". Never start a <title></title> with "The~" or "Welcome~" or "My" (unless the page-name actually includes the word "My" like "MyWebPages" in meaningful common-language use).
Page-ranks are partially dependant upon reliable, indexable terms and words like "the" and "welcome" are closer to dismissable.
I'd even opt for:
<title>Continental Products - Industrial and Construction Adhesives == == Welcome!</title>
As it puts the 'company name' FIRST, and thus, would be indexed better.