General Description: Optional pins which are not requested by the user still appear on the Foundation symbol generated by CORE Generator for the Virtex Dynamic Constant Coefficient Multiplier and Variable Parallel Multiplier modules.
Solution
This is a known problem with the 2.1i release of the CORE Generator.
Please refer to (Xilinx Solution #6853) for a description of the typical symptoms further down in the design flow, and the recommended workaround.