[vtkusers] vtkImageCanvasSource2D err

[Dean Inglis]

can someone please verify that vtkImageCanvasSource2D 
is not behaving correctly with the follwing tcl script?
I am observing corrupted pixels at the lower left corner
of the resultant image and at a spot lower right of 
center.  The fill operation should give a completely
red image.

package require vtk
package require vtkinteraction

vtkImageCanvasSource2D acanvas
[acanvas GetOutput] SetExtent 0 255 0 255 0 0
[acanvas GetOutput] SetNumberOfScalarComponents 3
[acanvas GetOutput] SetScalarTypeToUnsignedChar
[acanvas GetOutput] SetSpacing 1 1 1
acanvas SetDrawColor 255 0 0
acanvas FillPixel 1 1
acanvas Update

vtkImageViewer viewer
viewer SetInput [acanvas GetOutput]
viewer SetColorWindow 255
viewer SetColorLevel 127
viewer Render


Have I missed something here?  Changing the fill seed
to some other location does not change things.
Writing the output to a png or bmp file shows the same
output presented by the viewer.

Build is Proximal experimental dashboard.

Dean