[junkgear]

Make sure your Focusrite is not being used for system sounds.
Try holding down the N key while PT starts, which will force a playback engine refresh and should allow you to choose which sound device you want to use with PT.

If that doesn't work, you may want to try re-installing your Focusrite drivers, making sure you are using the latest for your OS.

If that doesn't work, try trashing your PT prefs.

Beyond that, we'll most likely need some more information about your system and setup in order to help you through your issues.