Hi Tone...
maybe this isn't the best place for your question; this might work better in the "Recording" forum... but quickly, I'd have to say it depends on the source material, and the encoder both. If you're DL'ing from KaZaa, some of those files are INTENTIONALLY corrupted by record companies, to discourage downloads.
Try this again in "Recording"... may work better for you... or even the "Dragon Cave"
Chad