Does not work with size bigger than monitor size/resolution! Rated 1 out of 5 stars

the idea of this addon is great, but it does not work for me. i am using ff 21.0 and win7.
it does "restore" wrong position and wrong size when i configure positon and/or size that is bigger than my screen resolution. i have a 19'' monitor and a resolution 1280x1024!
please check this, thanks.