This issue can be tagged as soleved.

Even though I've deinstalled McAfee AV a long time ago this piece of software still hurts my neck. Because I've found out that it isn't enough to just deinstall it. In order to completely remove every "service" that is linked to it, you'll have to download a tool called "MCPR.exe" from the official McAfee website that is able to remove everything that still recides on your PC.

This tool can be found under this link: http://us.mcafee.com/apps/supporttools/mcpr/mcpr.asp

That address book issues also had been related to the german locale settings. When you're using it then you're unable to select addresses (especially when using multisig lockboxes). So after switching to English (us) everything works like it should. That would explain why you haven't encountered any of this issues.