ogre does not set automatic world transform matrix?

conquerors

in my material,i declaration ->param_named_auto worldMat world_matrix


ogre throw an err msg when parsing my material file
err msg->

16:39:02: OGRE EXCEPTION(2:InvalidParametersException): Parameter called worldMat does not exist.  in GpuProgramParameters::_findNamedConstantDefinition at e:\projects\ogrecvs\branches\eihort_vc71\ogrenew\ogremain\src\ogregpuprogram.cpp (line 877)
16:39:02: Error in material Examples/BumpMapping/SingleLight at line 139 of Examples-Advanced.material: Invalid param_named_auto attribute - Parameter called worldMat does not exist.

help me,thanks