Error 419

I've been running Windows 7 Enterprise (64 bit) for a couple of months now, and PDFcreator 0.9.8 has been working fine up until now.  I installed it originally using an admin account, and have been using it without problems with a user-level account.

A couple of days ago it started throwing an error.  I don't recall what that error was, but I decided to try reinstalling PDFcreator to see if that would resolve the problem.  As the admin user I uninstalled, rebooted and reinstalled.  And it works for the admin account.  However, it no longer works for the user-level account.  The error it now gives is:

Error-Nr: 419 (Permission to use object denied)
Modul: modMain
Procedure: StartProgram
Line: 51720

Obviously this is a permissions problem, and it's interesting that it occurred around the same time as the latest batch of Microsoft updates.  I'd appreciate if someone could point me in the direction of which file or object is causing the problem.

Thanks, Liz