Pro Tools does not like the standard buffer setting in the Windows Apogee Groove Control Panel, therefore it must be changed:
- Completely close Pro Tools
- Open Windows start menu > All Apps > Apogee > Apogee Groove Control Panel
- Click the Buffer Settings tab
- Change the "ASIO Buffer Size" to anything but Auto. The suggested setting is 256 samples, but depending on how powerful your computer is this setting may need to be raised, or can be lowered.