[Open Babel] Problem with OBForceField::FindForceField in XCode

[Alain D. <ade...@fr...>]

I have a problem with the latest (2.3.0) version of openbabel in xcode. 
When I call :  OBForceField* pFF = OBForceField::FindForceField("Ghemical"); (or other available forcefield)
pFF return null. It work's well with the last version. 
The files like ghemical.prm are located in the standard folder : /usr/local/share/openbabel  (and also in /usr/local/share/openbabel/2.3.0
If I launch, for example, obminimize in the terminal I see all the forcefields and the program work well.
I try with the openbabel install program for macos and I have also compiled the library from the source code... the result is the same : pFF is always null !!!
I have the same problem with xcode 3 and xcode 4. 
I have found no solution for many days... thank's for your help !
I have not found on the web a source code project with xcode that use this library (ibabel for example)... so.. is there a solution ?
And excuse me for my very bad english !