[vtkusers] Segmentation fault vtkDEMReader

[Pa Set]

Testing a QT program with  vtkDEMReader, compiled with no error but 
exits at runtime with "segfault at 0 ip b65f7d31 sp bf842720 error 6 in 
libvtkIO.so.5.8.0[b6529000+4ce000]".
I'm definitely making some mistakes. Can anyone point out the right way?
Thanks in advance for all feedback
Paolo

The starting point is this example program 
http://www.vtk.org/Wiki/VTK/Examples/Cxx/Qt/RenderWindowUIMultipleInheritance, 
modified in this way *only*:
........
#include "vtkSmartPointer.h"
#include <vtkDEMReader.h>
#include <vtkImageData.h>

// Constructor
SimpleView::SimpleView()
{
   this->setupUi(this);

   // Read the file
   vtkSmartPointer<vtkDEMReader> reader = 
vtkSmartPointer<vtkDEMReader>::New();
reader->SetFileName("/usr/share/VTKData/Data/SainteHelens.dem");
     reader->Update();
......

_Some infos:_
Ubuntu 12.04 with QT + VTK from repos.
Debug gdb:

Thread [1] 7178 [core: 2] (Suspended : Signal : SIGSEGV:Segmentation fault)
             vtkDEMReader::ReadProfiles() at 0xb6e3fd31
             vtkDEMReader::RequestData() at 0xb6e40bbc
             vtkImageAlgorithm::ProcessRequest() at 0xb7aa6af3
             vtkExecutive::CallAlgorithm() at 0xb7a64d93
             vtkDemandDrivenPipeline::ExecuteData() at 0xb7a580e6
             vtkDemandDrivenPipeline::ProcessRequest() at 0xb7a5b74f
             vtkStreamingDemandDrivenPipeline::ProcessRequest() at 
0xb7bac111
             vtkDemandDrivenPipeline::UpdateData() at 0xb7a59fca
             vtkStreamingDemandDrivenPipeline::Update() at 0xb7badbf3
             vtkExecutive::Update() at 0xb7a654d6
             vtkDemandDrivenPipeline::Update() at 0xb7a58f6b
             vtkStreamingDemandDrivenPipeline::Update() at 0xb7ba8ffb
             vtkAlgorithm::Update() at 0xb79fcb43
             SimpleView::SimpleView() at 0x804bb59
             main() at 0x804b95c

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