[vtkusers] image cast problem

[Amy Dillavou]

I'm using a VTK image cast to convert to unsigned short and I get the
following error:

ERROR:  
vtkStructuredPointsReader (0x7c87f0): Unrecognized file type: #  vtk
DataFile Version 1.0 for file: /data/carotid.vtk

ERROR: 
vtkStructuredPoints (0x7c8990): Update extent does not lie within whole
extent

How should I go about fixing the update extent to work with my data
without breaking it for other data sets?

Thanks in advance
Amy