Your bounce is doing EXACTLY what you are telling it to do. The timing you are looking at is giving you the value of the duration of the regions in your song. As most songs have some sort of time based effect the bounce can and will be longer if you tell the bounce to include Audio Tail as this will invariably be the result of your time based effects.
Several users have already told you how to remedy this. Personally, I set a loop cycle when bouncing because I never start my recordings on the first beat of the first bar. So my transport display is always going to show longer that the actual length of the song as it will incorporate this area of silence or count in. Sometimes you might want to include Audio Tail, other times not. It makes perfect sense why it works the way it does. A lot of occasions, what a number or meter is reading may not be exactly what you think it is measuring. The manual can be your friend here as Pancenter points out.
Your title says 'Fix this annoying glitch'. Who are you talking to? This is a user to user forum. Apple don't come here and all of us just try to help each other out and I hope this helps you to understand exactly what is going on and why.