I'm trying to export to autocad, but when I do I get a message saying:

"Warning: two items found when one was expected" then the program pretty much freezes, I get the nice little spinning beachball of doom mouse (the "computer is thinking" mouse for macs) for ages and after a long, long wait, I have to force quit. Before I get the two items message, I get something abou my mesh having too many vertices and converting it into individual polyfaces. I tried exporting with both dwg and dxf, and also changed the setting to export as polyfaces, but to no avail. Arg. Imminent deadline and rising stress levels don't help. Ay suggestions would be greatly appreciated. Is there any way to export to autocad indirectly?