VBNET eDrawings OCX Control DWG Read Error

Hi All.

I'm developing a small VB NET 2008 application that reads a Path ina Database and Open the right files on my disks with eDrawings2009. I embedded the OCX control and I call the following functioncorrectly:
edrwControl.OpenDoc("C:\sample.sldprt", True, True, False, "")

All works fine with sldprt files. But Always crash with DWG files.

I'm also tried to start a separate process with:

System.Diagnostics.Process.Start("C:\Program Files\CommonFiles\eDrawings2009\EModelViewer.exe", "C:\sample.dwg").

Also here, works fine with sldprt and crash with DWG.

If I open eDrawing without VB (as usual), I can read correctly bothfiles: sldprt and dwg.

Please, Have You any suggestion about it?
Thank You very much for Your answer!
GabrieleSolidworksEdrawings