Program: 11776
Project: 11776
Buggy source:
private void createFormArea(Composite parent){
  final IObservableValue master=ViewerProperties.singleSelection().observe(viewer);
  ctx=new EMFDataBindingContext();
  addStatusSupport(ctx);
  form=toolkit.createForm(parent);
  toolkit.decorateFormHeading(form);
  form.setText("String_Node_Str");
  Composite body=form.getBody();
  body.setLayout(new GridLayout(2,false));
  IWidgetValueProperty prop=WidgetProperties.text(SWT.Modify);
{
    final IEMFValueProperty shortProp=EMFEditProperties.value(editingDomain,ProjectPackage.Literals.PROJECT__SHORTNAME);
    ;
    toolkit.createLabel(body,"String_Node_Str");
    Text t=toolkit.createText(body,"String_Node_Str");
    t.setLayoutData(new GridData(GridData.FILL_HORIZONTAL));
    ctx.bindValue(prop.observeDelayed(400,t),shortProp.observeDetail(master));
    final IEMFValueProperty longProp=EMFEditProperties.value(editingDomain,ProjectPackage.Literals.PROJECT__LONGNAME);
    toolkit.createLabel(body,"String_Node_Str");
    t=toolkit.createText(body,"String_Node_Str");
    t.setLayoutData(new GridData(GridData.FILL_HORIZONTAL));
    ctx.bindValue(prop.observeDelayed(400,t),longProp.observeDetail(master));
    ctx.bindValue(FormTextProperty.create().observe(form),new ComputedValue(){
      private IObservableValue shortname=shortProp.observeDetail(master);
      private IObservableValue longname=longProp.observeDetail(master);
      @Override protected Object calculate(){
        return shortname.getValue() + "String_Node_Str" + longname.getValue();
      }
    }
);
  }
{
    IEMFValueProperty mProp=EMFEditProperties.value(editingDomain,ProjectPackage.Literals.PROJECT__START);
    toolkit.createLabel(body,"String_Node_Str");
    Text t=toolkit.createText(body,"String_Node_Str");
    t.setLayoutData(new GridData(GridData.FILL_HORIZONTAL));
    ctx.bindValue(prop.observeDelayed(400,t),mProp.observeDetail(master),new EMFUpdateValueStrategy().setConverter(new StringToDateConverter(NLSMessages.ProjectAdminViewPart_StartDateNotParseable)),new EMFUpdateValueStrategy().setConverter(new DateToStringConverter()));
  }
{
    IEMFValueProperty mProp=EMFEditProperties.value(editingDomain,ProjectPackage.Literals.PROJECT__END);
    toolkit.createLabel(body,"String_Node_Str");
    Text t=toolkit.createText(body,"String_Node_Str");
    t.setLayoutData(new GridData(GridData.FILL_HORIZONTAL));
    ctx.bindValue(prop.observeDelayed(400,t),mProp.observeDetail(master),new EMFUpdateValueStrategy().setConverter(new StringToDateConverter(NLSMessages.ProjectAdminViewPart_EndDateNotParseable)),new EMFUpdateValueStrategy().setConverter(new DateToStringConverter()));
  }
  addTabArea(ctx,master,body);
  body.setBackgroundMode(SWT.INHERIT_DEFAULT);
}

Fixed version (ground truth):
private void createFormArea(Composite parent){
  final IObservableValue master=new WritableValue();
  IObservableValue treeObs=ViewerProperties.singleSelection().observe(viewer);
  treeObs.addValueChangeListener(new IValueChangeListener(){
    public void handleValueChange(    ValueChangeEvent event){
      if (event.diff.getNewValue() instanceof Project) {
        master.setValue(event.diff.getNewValue());
      }
    }
  }
);
  ctx=new EMFDataBindingContext();
  addStatusSupport(ctx);
  form=toolkit.createForm(parent);
  toolkit.decorateFormHeading(form);
  form.setText("String_Node_Str");
  Composite body=form.getBody();
  body.setLayout(new GridLayout(2,false));
  IWidgetValueProperty prop=WidgetProperties.text(SWT.Modify);
{
    final IEMFValueProperty shortProp=EMFEditProperties.value(editingDomain,ProjectPackage.Literals.PROJECT__SHORTNAME);
    ;
    toolkit.createLabel(body,"String_Node_Str");
    Text t=toolkit.createText(body,"String_Node_Str");
    t.setLayoutData(new GridData(GridData.FILL_HORIZONTAL));
    ctx.bindValue(prop.observeDelayed(400,t),shortProp.observeDetail(master));
    final IEMFValueProperty longProp=EMFEditProperties.value(editingDomain,ProjectPackage.Literals.PROJECT__LONGNAME);
    toolkit.createLabel(body,"String_Node_Str");
    t=toolkit.createText(body,"String_Node_Str");
    t.setLayoutData(new GridData(GridData.FILL_HORIZONTAL));
    ctx.bindValue(prop.observeDelayed(400,t),longProp.observeDetail(master));
    ctx.bindValue(FormTextProperty.create().observe(form),new ComputedValue(){
      private IObservableValue shortname=shortProp.observeDetail(master);
      private IObservableValue longname=longProp.observeDetail(master);
      @Override protected Object calculate(){
        return shortname.getValue() + "String_Node_Str" + longname.getValue();
      }
    }
);
  }
{
    IEMFValueProperty mProp=EMFEditProperties.value(editingDomain,ProjectPackage.Literals.PROJECT__START);
    toolkit.createLabel(body,"String_Node_Str");
    Text t=toolkit.createText(body,"String_Node_Str");
    t.setLayoutData(new GridData(GridData.FILL_HORIZONTAL));
    ctx.bindValue(prop.observeDelayed(400,t),mProp.observeDetail(master),new EMFUpdateValueStrategy().setConverter(new StringToDateConverter(NLSMessages.ProjectAdminViewPart_StartDateNotParseable)),new EMFUpdateValueStrategy().setConverter(new DateToStringConverter()));
  }
{
    IEMFValueProperty mProp=EMFEditProperties.value(editingDomain,ProjectPackage.Literals.PROJECT__END);
    toolkit.createLabel(body,"String_Node_Str");
    Text t=toolkit.createText(body,"String_Node_Str");
    t.setLayoutData(new GridData(GridData.FILL_HORIZONTAL));
    ctx.bindValue(prop.observeDelayed(400,t),mProp.observeDetail(master),new EMFUpdateValueStrategy().setConverter(new StringToDateConverter(NLSMessages.ProjectAdminViewPart_EndDateNotParseable)),new EMFUpdateValueStrategy().setConverter(new DateToStringConverter()));
  }
  addTabArea(ctx,master,body);
  body.setBackgroundMode(SWT.INHERIT_DEFAULT);
}