A System.Runtime.InteropServices.COMException is thrown when I try to open SolidWorks files using the SldWorks.OpenDoc6 method. The message of the exception is "The RPC server is unavailable. (Exception from HRESULT: 0x800706BA)."

A few internet searches tell me that this is a common Windows error caused by some sort of network communication hiccup. However, none of the usual culprits for the error apply in my situation. The Remote Procedure Call service is running on my computer and on the PDM Archive and Database Servers. I can ping those servers using their server names. I can telnet to those servers on port 135.

I'm at a loss as to why I see so many of these exceptions in my debug log. Has anyone else encountered this before?