With CSV Connector V3 released in Q4 2012, we deprecated the export tab within the CSV Connection. Instead we created a new Export Component which is located in the Other Tab within components window. This export button allows developers to enable the same export functionality without requiring web services.
If your organization was previously using CSV Connector Export functionality and move to V3, when you open a dashboard project (XLF file) that contains export properties that have been bound, the Export tab will re-appear for your continued use to ensure forwards compatibility.