Firefox is not the only program I'll have running at one time so it's often minimized on my taskbar. If you hover over it I can see the tabs I have in the current session. However, if I'm working in another program and hover back to firefox to open one of my tabs it opens full screen and suddenly shrinks to half the size of my screen. It does this 90% of the time. I'm not opening it any differently than I used to, but often when I click over my minimized tabs to restore one to full screen it opens and then instantly shrinks to half of my screen. Why does it keep doing that? It's very frustrating to open the tab and then have to maximize it so frequently.