Hi,
I recently started using ardour and have since upgraded my ubuntu gutsy install to ubuntu studio. Yesterday I recorded several tracks for a song on my tascam hard disk recorder and exported them as wavs to import into ardour. This was done on my bandmates pc and we eq’d and mixed them etc. I then copied the project folder to a USB stick so I could work on it from my machine. Unfortunately, on my laptop it is playing around a semitone lower and at a slower speed, like the shuttle speed has been set lower. Am I missing something obvious in my/his settings or is transferring the song not as simple as I have assumed?
samplerate is the answer 
you probably imported files created at 48kHz, and you are using your soundcard at 44.1kHz.
If your soundcard can run at 48K you can start JACK in 48000 instead of 41000 then it will sound well.
Ubuntu gutsy gibbon had a lots of bug. But jonty jacklop is cool. I use it as my native linux operating system.