Could be the “Project Rate” in your Audacity window was set wrong.
That’s the box in the lower-left corner of the main window (at least
in Audi126). I’ve had that happen before as it auto-changes when
you import (for example) a non-44100 sample rate file.
I dont know, but as I say, second attempt and it was ok.
Ive noticed putting two or three diff music clips on a file and often they will be at diff speeds,
it must be, as you say, the bit rate chosen …
In the past Ive always highlighted the section of music, hit on effects…
then speed… and been able to adjust things
you can adjust it then hit to hear a sample 4 seconds to see if it sounds right .
That’s because the old Audacity 1.2.x series do not support multiple sample rates in the same track. Audacity 1.3.14 does not have this problem and neither does the new Audacity 2.0 which is due to be released very soon.
Audacity 2.0 is due to be released very soon, so it may be worth waiting for that.
If you want to receive an e-mail when Audacity 2.0 is released you can register your interest at the bottom of the Audacity home page: http://audacityteam.org/