When save dgn file as dwg (dxf) - a lot of styles changed (got other styles). Error?

I need will get drawing from dgn V8 file for Autocad. And when  i export file in dwg or dxf  - i get dwg, dxf file with other (changed) styles lines and features. I load this dwg (dxf) file back in microstation - styles changed. Why this happened?saveAsDwgChangeStyles.dgn