When using an external clock source with Pro Tools, you may on occasions accidentally set the clock to a different sample rate to that of the session. I've done this myself on a couple of occasions and it causes speed issues for any audio you record.

In this video I demonstrate how you can end up with audio recorded at the incorrect sample rate and so play too fast or too slow and so at the wrong pitch.  I then demonstrate how you can resolve this problem using sample rate conversion in the Pro Tools Import Audio window.