Since last AECC update (AE v18.104.22.168), a friend noticed what appears to be a bug around audio output settings (in the output module). Strangely enough, audio output default settings are now set at 8,000 khz, rather than 41,000 khz like it used to. The bug is that no matter what change you make to these settings, it keeps reseting itself to 8,000 khz. Once export is done, it appears the audio track was kept at 41,000 khz. However, every time we looked back on the audio settings, it kept showing these at 8,000 khz.
Search the forum. This is a known issue and Tim Kurkoski has explained how to handle this in the relevant thread.
I did search the forum but I was using more specific terms, which led to not finding anyting! Finally found it with more general terms, and so It's a known issue since a month... http://forums.adobe.com/message/6005692#6005692