Yes, that should work. But you need to create at least one visualization module in mayave, e.g. Surface (this can be done also from the command line: mayavi2 -d cylinder.vtk -m Surface), and set the data source to correct field.

As for the original problem - do you use WX widgets for both mayavi and matplotlib? If so, try setting (just guessing) the matplotlib backend to something else, as sfepy might import matplotlib somewhere during postproc.py call.