[vtkusers] Mac OS10.3.2 : Weird undefined symbol

[David Bernstein]

VTK 4.2.3 suddenly stopped working, I swear I didn't change a line of 
code!

This is what I get

dyld: /Users/dave/Projects/ReDi/bsd Undefined symbols:
/Users/dave/Projects/ReDi/bsd undefined reference to 
__ZN19vtkUnstructuredGr\340 expected to be defined in 
/Applications/VTK/vtk-src-unix/bin/libvtkCommon.dylib
Program received signal:  "SIGTRAP".

The line in my code that gdb quits on is:

mpVtkGrid->InsertNextCell(mpVtkTriangle->GetCellType(), 
mpVtkTriangle->GetPointIds());

What I'm doing here is loading an instance of vtkUnstructuredGrid with 
data from my own mesh class.

Has anyone seen this before?

Thanks,
Dave