Pro Tools 5.1.3cs7 & 5.3.1cs2 both contain the same fix relating to control surfaces only.
For Pro Tools|HD systems, download and information:
http://www.digidesign.com/download/cs/531cs2/
For Pro Tools|24 & MIX systems, download and information:
http://www.digidesign.com/download/cs/513cs7/
(also linked from the Pro Tools section in Support/Downloads)
What's Fixed in Pro Tools 5.3.1cs2?
Fixed: Potential Crash when Starting Playback while Changing Parameter Values via Control Surfaces
When entering playback, while simultaneously modifying parameter values via a compatible control surface, Pro Tools may crash if one or more tracks are record enabled.
Regards,
Digi Pro Tools Team