How do I keep the 128Kbps CBR audio when adding it to video?

[BMurray]

I'm adding video this year to my first halloween display. I can't seem to keep the 128 CBR for the audio when adding it the video. It keeps changing to 195kbps. I'm able to attach the "new" audio file to my sequence and it plays fine. But I notice it is slightly off with the sequence but in sync with the video. I'm sure it has to do with the bit rate but can't figure out how to keep the 128 CBR.

ANY HELP IS GREATLY APPRECIATED !!