I have of them working together in their GDK versions.
I havent fully tested them but I have created a simple object terrain, created and entity and waypoints and set it off patrolling, with DarkAI, and made a bunch of small cubes rigid bodies that drop down onto the terrain with DarkPhysics..
Other than that I havent really played too much with the physics side yet.
On a side note, I also have the "Sparky's Collision Library 2.05b" included in the project and call some of his collision routines for my ai entities, it works fine with DarkAI and DarkPhysics aswell so far.
The only problem that I have had with it, is with Advanced Terrain in GDK, it throws a linker error for multiply defined symbols as soon as you call dbSetupTerrain..or any other terrain command.. still waiting on support to get back to me about that lol
I am using DarkGDK 7.3, March 2009 DirectX SDK, Latest downloadable versions of DarkAI and DarkPhysics.
If it ain't broke.... DONT FIX IT !!!