PDFCreator COM object will not convert an html file, yet it will work for .XLSX

When I use the sample com applications (.net and .vb) I am able to convert an Excel file to PDF, yet html will not work. It simply hangs up.  If I print using the PDFCreator driver rather than the com object the HTML will convert to PDF just fine.

What am I doing wrong?

ANSWER: you cannot use the cPrintFile() method to print an HTML file. Instead use the cPrintURL() method.

ANSWER:

You cannot use the cPrintFile(filename) to print an HTML file. But instead use the cPrintURL(filename).  Unfortunately none of this is documented.