DirectShow, problem rendering avi video with bad header

[paolob]

I have some avi video not well formed. GSpot tells me the header is corrupted.
But if i try opening them using Media Player Classic all works good.
Instead when I try opening them using Directshow GraphBuilder.RenderFile() it doesn't play. I report a piece of code:

********* Defined in .h *****************
IGraphBuilder *m_pGraphBuilder;
*****************************************

CoCreateInstance( CLSID_FilterGraph, NULL, CLSCTX_INPROC, IID_IGraphBuilder, (void **)&m_pGraphBuilder);

m_pGraphBuilder->RenderFile( wFile, NULL);

I analized the graph of both my software and media player classic using GraphEdit. Changing some MPC options (but alwais checking the video can play), I obtained 2 graph with one only difference, the Avi splitter:
MPC uses Avi Splitter (low merit),
RenderFile builds a graph using Avi Splitter.

Does someone know how can I render that files in my code?
Thanks for any help.