partnmesh (Metis 4.0) bug ??

I try to part a mesh which consist of two triangles into 2 parts.
minimal.mesh

2 1
1 2 3
2 3 4


The commandline is:
partnmesh minimal.mesh 2

But the result for minimal.mesh.npart.2 is:

0
0
0
0

and for minimal.mesh.epart.2:

0
0


At least for the elements i had expected 0,1...
What is wrong ???