Problem with COM Interface

I’m using the COM interface usign VBA from access 2010, Windows 7 64 bits and PDFcreator 1.5. 

My code is based in the code sample provided  by PDFcreator, and works fine. The problem is that ocasionally, the COM Object does not return to Access, and a COM message is show: 

Error: Action Cannot Be Completed Because The Other Application Is Busy. 

The only way to continue printing is killing the pdfcreator.exe process using the windows task manager.

The code works like this:
for a given records:
1. set PDFCreator as the default printer.
2. Create the pdfcreator objetc Set PDFCreator1 = CreateObject(“PDFCreator.clsPDFCreator”)
2. Configure PDFcreator using the COM interface to autosave to a file, encripted
3. Retrieve the generated filename
4. Close the PdfCreator object.

Alas, sometimes PDFCreator never returns after printing

Any ideas?