Maybe it's not the right place to reply but just in case
I had the same king of issue with Avast 6 and PowerDVD 9 and 11
To fix the problem, I just added the following path to the trusted program list in the last agent ("suspicious actions" ? sorry my Avast is in French)
C:\Program Files (x86)\CyberLink\PowerDVD11\Common\NavFilter\CLHelper.exe
After this, no problem anymore... I could finally enjoy my BD !
Hope this help
