XviD doesn't want to encode my audio right?

[agerlords]

I am using FRAPS to collect game footage for a review (running about 10 minutes in total) and I used the bitrate calculator to determine what would be the best solution for my video bitrate for a file size around 100mb. So I set it at the suggested (which happened to 1233kbps if I recall correctly) and it turns out to render around 250MB with mediocre quality. Now I can take the mediocre quality as it comes with the desired file size, but it should NOT be that big. My first thought was that my Codec might have been corrupted or something, but after reinstalling it and retrying futilely I noticed something strange. I opened up the .avi with VLC and checked the codec info I was astounded to see the Audio Bitrate was set around 1500kbps. Thinking it was my mistake, I re-rendered it and was sure to set it to 128kbps in the Xvid encoding manager, but the same thing happened. Any suggestions would be appreciated at this point, this is really screwing up my filesizes and making me want to get out of encoding all together. :/ I tried Sony Vegas 9.0 Pro and VirtualDubMod, the only difference is the files with VDM were even bigger.

[paglamon]

was sure to set it to 128kbps in the Xvid encoding manager

You have to set it under Audio compression/Lame mp3 in Virtualdub. How can you set the audio bitrate in XviD,which is a video encoder? When you put the audio bitrate in XviD,it is only to calculate the Video bitrate available to XviD for the given size of the file.