PublishToPdf is failing me and I can't figure out why

So I'm writing an application in C# that will load artwork into a template file, do some manipulations and then save that file to a printer hotfolder as a pdf.  

Everything works fine up to the point where I actually do the publish.  I keep getting a Com error HRESULT E_FAIL, which is of little help.   I've change all my pdf settings a million different ways, wrote my file paths a million different ways, and yet i'm getting nowhere.  If I do this all manually or if I do it via VBA it works fine, so i'm guessing it has something to do with the interfaces im using but I really have no idea.  If anyone has some advice that would be greatly appreciated.  (If anyone knows how to execute a macro via the C# api, that would be a work around I am interested in. 

This is essentially what I'm doing just whittled down to the bones. 


private void sample()
VGCore.Application App;
VGCore.Document Doc;

//open app
Type pia_type = Type.GetTypeFromProgID("CorelDRAW.Application");
App = Activator.CreateInstance(pia_type) as VGCore.Application;

//open doc
Doc = App.OpenDocument(@"C:\Blank template.cdr");

//import art

//work with art

//set pdf settings here

//publish final product to pdf

//^^this line fails everytime : Error HRESULT E_FAIL has been returned from a call to a COM component.