We are using Audacity to record speaking contributions of Students in lessons. What we are finding is that the record/playback levels fade away after around four minutes. Does this also happen to you?

I can't provide more detail on Audacity versions as the news broke today as I was leaving the site. I would like to be able to go into work tomorrow armed with more information. Can anyone help with information as to how they have dealt with something similar in their own schools.

PC OS: XP Pro: SP3.

Hardware: Various vendors including Dell and Viglen laptops. Also implicated: Built in condenser and external microphones.