Tech Stocks Open Lower on Cisco; Dow Flat  NEW YORK (Reuters) - U.S. tech stocks opened lower on  Wednesday, as results from technology bellwether Cisco Systems  Inc. &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=CSCO.O target=/stocks/quickinfo/fullquote"&gt;CSCO.O&lt;/A&gt; disappointed Wall Street, while investors await  an expected hike in interest rates from the Fed later in the  day.