Works as intended, but ended up disabling it when I discovered it is the reason that Firefox is never idling. So I have many tabs, and this plugin is always keeping 10% of the CPU busy (2 processes at 5% each). Disabling the plugin makes the problem go away. My version is 1.0.7.

The workaround mentioned in the FAQ did not work: count only active tabs setting did not make a difference for me.

The reason mentioned in the FAQ for this behaviour is:

> LeechBlock reviews all open tabs every second, to keep track of how much time is spent on the sites listed in your block sets and to determine whether any sites should now be blocked.

I do not need this "feature", I just want to disable access to certain websites from 9 to 5. Since I can't disable the feature, I had to disable the addon and search for a simple one.