NAV 2009 blocking PDFCreator, other fine app's

A few days ago I "upgraded" to NAV 2009 from NAV 2008. I did an upgrade installation. It went fine.

 

Today I realized my print-to-PDF application, PDFCreator, wasn't working, and eventually found NAV2009 was blocking it from running. My history showed the Actor: c:\program files\pdfcreator\pdfspooler.exe, was targeting C:\Program Files\Norton AntiVirus\Norton AntiVirus\Engine\16.1.0.33\ccSvcHst.exe and the Action: Open Process Token, with the Reaction: Unauthorized access blocked.

 

I went through three Symantec support sessions:

  1. Support person toggled NAV settings on and off. Restarted with select services. I incorrectly said everything was fine but failed to realize NAV hadn't restarted and so it wasn't blocking the app.
  2. Next support person flagged remnants of previous NAV installs so did a complete deinstall including registry and other file cleanup. After getting NAV reinstalled and running Live Update, then confirming NAV was running, application was okay. I thought I was clear. But hours later, NAV started blocking the app again.
  3. Started yet another support session and support person tried going over the work of the last two. After some more Live Updating, application was no longer being blocked.

And a few more hours later, it's still working.

 

Any idea what happened here?

 

Also, now I see in my history NAV is blocking another application, acs.exe, a process for my Atheros Wireless LAN (same target, same reason, same reaction).

 

Why?

 

Both of these applications are clean. They were never an issue in NAV2008, but I'm having a heck of a time with them here with NAV 2009.

 

Please help!