Converting to XviD with Vidomi - Audio Problem

Hello, I’m new to ripping from DVD, so apologies if I miss out a vital bit of information.

Basically, I’m using DVD Decrypter to rip VOB files onto my HD and importing them into Vidomi to compress to a Two Pass XviD VBR AVI file.

The XviD part of the conversion is fine; the video is perfect. But the audio is not so great… Here’s my settings -

Lame Dual Channel (I assumed that was Stereo?) MP3 @ 128kb/s, with the freq. set at ‘same as source’.

I’ve been using a one pass normalize at 75% as anything over clips, as does 2 pass normalize.

My problem is the audio slowly decreases in volume when playing back the AVI. In some files there are also dips. I’m assuming this is something to do with the normalization process?

Any help would be awesome as this is driving me crazy. Thanks.

Here’s a screenshot of the audio settings page: