SlicerIGT/VolumeResliceDriver — pull request #5 by lchauvin (2013-05-24 19:20:13+00:00)
Title: BUG: Fixed reslicing deformation with ruler

It seems there is something wrong the "Cross" methods.
I don't know if it's related but the cross method in your code doesn't have a scope in front of it (vtkSlicerVolumeResliceDriverLogic).
I replaced it with the Cross method of vtkMath and it seems to work.