Strange problem with pinning an icon to taskbar

Something weird has happened to my taskbar. I have a few programs pinned there and everything was okay. Then today I unpinned Firefox from there because I wanted to change the icon I was using. After deciding I didn't like it I tried to go back to the one I was using but when I pinned it back to the task bar this problem occurred:



As you can see when I click on the silver Firefox icon, it opens up a new firefox icon (default icon) in a separate place, taking up unnecessary space. I can't figure out how to make it go back to the way it was where everything stayed within the silver icon.

It is indeed the browser being opened but the problem is it used to open up within the silver icon (the default firefox icon you see to the right has basically taken its place). It's a bit of an annoyance because it takes up the little space I have on my taskbar before things start getting combined and messy.

Sorry if what I'm explaining is confusing, it would probably be easier to show with a video or something.

Ok maybe this will help explain my situation a bit better

in this screenshot:



You can see I have foobar opened up and when you look at the taskbar you can see that the silver foobar icon is in use and there is no default foobar icon off to the right somewhere. But when you look at the silver firefox icon you can see that it is not in use and that the default icon to the right is the one that contains all my open tabs and what not. I have been trying forever to make it go back to the way it was where my silver FF icon was the only one in use and not the default one but I just can't seem to make it happen. Funny thing is that i have had this problem in the past but for the life of me cannot remember how I fixed it.

Well it looks like a simple reinstall of Firefox did the trick. I noticed this wasn't happening with any other programs so it had to be a quick fix.