Doctor M said: If you only let Womble re-encode audio at edit points (as opposed to fully re-encoding), you can get weird volume fluctuations at edit points.

Here's why: Stream copied ac3 leaves the dialog normalization level untouched. Re-encoded segments have the normalization re-set to -31db (regardless of what you tell Womble to use as the audio source reference).

Is this the only reason why the received wisdom amongst Womble users was to check the re-encode the whole audio if any part needs re-encoding option? I used to run into problems with players choking on DVDs made from files exported from Womble, so I always used to check this option, along with Gop size compliance for DVD recording and use CRC protection.