[Insight-users] ask for help: Exception for DeformableRegistration4

[he smth]

I use DeformableRegistration4 for dicom files registration
so I modify it as(I1.dcm and I2.dcm are two dicom files in F:\): 
////////////////////////////////////////////////////////////////////////////////
const    unsigned int    ImageDimension = 2;
  typedef  short           PixelType;
......
itk::DICOMImageIO2Factory::RegisterOneFactory();

  fixedImageReader->SetFileName(  "F:\\I1.dcm" );
  movingImageReader->SetFileName( "F:\\I2.dcm" );
///////////////////////////////////////////////////////////////////////////////
when it run 
 registration->StartRegistration(); 
a exception is throw:

IFLAG= -1. LINE SEARCH FAILED. SEE DOCUMENTATION OF ROUTINE MCSRCH
ERROR RETURN OF LINE SEARCH: INFO=3 POSSIBLE CAUSES: FUNCTIION OR
GRADIENT ARE INCORRECT OR INCORRECT TOLERANCESvnl_lbfgs: ** EEEK **
ExceptionObject caught !

//bow for any help!!