The custom memory allocator for both Recast and Detour are submitted in R178 in SVN. The latest update also fixes the Visual Studio project and one array allocation bug which surfaced in VC.
As highlighted in the previous post, the API has changed on how the objects are required to be constructed. There is now alloc and free functions for each object (dtNavMesh, rcHeightField, etc). I used the same pattern all over the place, so it should be easy to spot.
[EDIT] Few more bugs were still there. Folks living at the SVN edge, please try R183.