IFilter_design_example.m Warning

Im running Matlab R2012a - student version. When I download and run IFilter_design_example.m I get this warning (at this point nothing has been modified its just as is out of the lecture website):


Warning: Ignoring all input names because of name conflicts.
> In warning at 26
  In DynamicSystem.DynamicSystem>DynamicSystem.plusInput at 1080
  In DynamicSystem.DynamicSystem>DynamicSystem.plusMetaData at 924
  In InputOutputModel.plus at 59
  In InputOutputModel.InputOutputModel>InputOutputModel.minus at 458
  In getZDZN at 66
  In IFilter_design_example at 34

Does anyone else see it? The plots and all look fine but I was curious coz it says "Ignoring all input names...".