Unable to bounce in logic pro 9 with realtime mode on.

Hello Friends,

After completing my project, I want to bounce the project into mp3. I selected Realtime mode with bounce 2nd cycle pass and include audio trail.

In normalise i selected overload protection only.When the bouncing started,it took its two usual rounds and then its generally over. The bounce is done. But This time it did not stop. It just went on for almost 10 rounds so i had to stop it manualy.

why is this happening?

Any clue?

Please reply asap, as my project is pending.

Thanks.