[vtkusers] Filters calling other filters

[Kalle Pahajoki]

Hi

I have a piece of code that seemed to work / worked with VTK 4.4 where a 
filter calls
vtkImageGaussianSmooth (on the output data it is producing) as a part of 
it's execution. With the CVS version of VTK it now fails with error: 
ProcessRequest invoked during another request.

Why is there such a limitation, and how should I change my code to get 
similiar functionality?

Kalle