When you freeze an app with TiBu just check your app drawer. If the app no longer shows in your app drawer than it is frozen. Pay no attention to that drooling idiot task manager. Most of them are epic fails.
And as VS said, if you downloaded it, or it can be downloaded from the market, the app will always show up on the market whether you have it frozen or not. Sometimes, not always, you have to restart your phone after installing TiBu so it grabs root permission correctly and then it works perfect.