Xtra (Havok Physics Scene)

Yes I do play games with my MBP, on some games I get this NOTE: This applicaction requires an Xtra (Havok Physics Scene) that either does not exist or faliled to initialiize properly. Please make sure the
appropriate Xtras folders.

Ok ,I have the up to date shockwave 11 (full version), does any body now anything about this?,How do I get Havok Physics Scene Xtra?.

Thanks