IIS ISAPI Application Can't CreateDC for PDFCreator (Win7 x64)

I just installed the latest PDFCreator on my Win7 x64 machine. I configured it to AutoSave and that works fine with NotePad but my C++ ISAPI application is unable to successfully call CreateDC for PDFCreator. This application has been able to use other printer drivers, though that was on XP / 2003 OSs. So the problem may be an OS / permission problem rather than a PDFCreator problem.

Has anyone else had this problem?

Is there a log somewhere that will give me more information about why it is failing?