Costco Disappoints on Profit, Stock Falls  NEW YORK (Reuters) - Costco Wholesale Corp. &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=COST.O target=/stocks/quickinfo/fullquote"&gt;COST.O&lt;/A&gt;, the  largest U.S. warehouse club, on Thursday posted a 21 percent  rise in quarterly profit but its shares fell after it failed to  beat expectations.