hldj.org

For those of you using Audacity for audio conversions, there is a confirmed bug where it tends to add extra silence to the end of your track when you resample it (i.e. change the frequency). The solution to get around this is as follows:
Before exporting to wav, select Project > Quick Mix (or if you are using the beta version, Track > Mix and Render). This will make the silence appear in the editor, from which you can simply highlight it and delete it, before continuing on to export it.
Hope that helps.