The reason you don't see that screen beside the bubble is because you have not joined your contact page with your contact making one page, in the top right of your screen you have 4 things you can do, try clicking the very first one and watch what happens when you are online with someone, then you will understand totally.
I agree, the answer marked as the solution is not the solution for everyone. It didn't work for me or for my friend, on Win 7 home edition. Sometimes the bar slides open and closed by itself but there's no way to make it stay put away. It's as though something the computer's doing is making it happen. Maybe it recalculates the mouse pointer position or something.
Whatever's going on, the bottom line is that it's extremely annoying to not be able to control the stupid thing, and the bar's behavior is highly distracting and intrusive.
I would like to be able to opt out of that call bar and use a static bar or just use the menu commands.