it did some grep in the profile directory and found that user.js might be the source that extensions.blocklist.enabled automatically changes its value to true

Therefor I set user.js->user_pref("extensions.blocklist.enabled", false);. Since then I did 2 restarts and each time extensions.blocklist.enabled has the correct value which is false.

I'm now lurking if something changes, and if so, Ill notice you 4 sure.