adjncy adjidx

I need the help of someone familiarize with partitioners. I'll try to explain my problem. I have a graph provided by an application and was partitioned by METIS (METIS_PartMeshNodal). I have put in a file METIS adjidx and METIS adjncy list in order to read them with another partitioner, but it fails, it returns: the number of edges doesnt match, and this is due to the comprobation that this partitioner makes when tries to read a graph with a wrong format from a file. I think I only need to apply a METIS function before writting the adjacency list to the file. I have tried MeshtoNodal, MeshtoDual an nothing.