Ciena Posts a Loss, Forecasts Flat Sales &lt;p&gt;&lt;/p&gt;&lt;p&gt; By Deborah Cohen&lt;/p&gt;&lt;p&gt; CHICAGO (Reuters) - Telecommunications equipment makerCiena Corp. &lt;CIEN.O&gt; on Thursday reported a wider loss for thefiscal third quarter due to slack demand and forecast sales inthe current quarter would be little changed from the thirdquarter.&lt;/p&gt;