[vtkusers] Deleting imagedata

[prieto at creatis.insa-lyon.fr]

Hello vtkUsers

I have an application where I can load images and show them in a viewer
and execute different filters etc.
Everything goes fine in the application until I want to work with a second
image.
After I have load the image I've notice the application does not
deallocate the previous image, if I continue to load other images, it
starts eating memory to the point it crashes or gives unexpected
behaviour.
I have checked the reference count of the previous image and it always
gives me 3 references even after I have set the new image into the
application.
I have tried many things to deallocate the old image without succeed for
example:

//I have an attribute from the class somewhere
vtkImageData* _oldimg;

...
//somewhere in the code after I have set the new image I've tried things like
_oldimg->Delete();
//Or
_oldimg->SetReferenceCount(0);
//Or the previous both
//Or
vtkGarbageCollector::UnRegister(_oldimg);


etc.....

The application either does nothing and continues to eat memory or it
gives assertions or segmentation faults.

Any help will be really appreciate it.

Thank you