Gateway Posts Operating Profit  SAN FRANCISCO (Reuters) - Personal computer maker Gateway  Inc. &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=GTW.N target=/stocks/quickinfo/fullquote"&gt;GTW.N&lt;/A&gt; on Thursday posted its first operating profit in  nearly three years as its retail strategy gained traction and  costs fell, sending shares up 11 percent.