you could try re-editing the slience added out with a program such as Nero Wave Editor, which despite its name will edit mp3 as well.
> Already thought of that and found a digit to set to zero
> for CD purposes but it hasn't made any difference. There's
> no problem saving files as .wav, but there is as .wma and
> .mp3. Something to do with encoding and compressing maybe?
> Also the silence added seems to be of random lengths, not
> the same each time.