LESModel is not a member of compressible?
 

I am doing an evoluzione solver in OpenFOAM-1.6
And I make definition of a turbulence pointer like this

Info << "Creating turbulence model.\n" << endl;
autoPtr<compressible::LESModel> turbulence
(
compressible::LESModel::New
(
rho,
U,
phi,
thermo
)
);

But it is very strange, there comes error like

createFields.H:87: error: ‘LESModel’ is not a member of ‘Foam::compressible’
createFields.H:87: error: ‘LESModel’ is not a member of ‘Foam::compressible’

I don't understand why, cause LESModel is a class defined in compressible. and it should be accessed by Foam::compressible::LESModel

And I used to run the same stuff in OpenFOAM-1.5, but there is no error like this..

Is there any difference between 1.5 and 1.6 for LESModel? What should I do?

Help,help,help!!!!!!!!!!!!!!!!!