Magnetic field not active in 10.06.p01

Hello,

we just produced some test samples with the 10.06.p01 version and realised that our magnetic field not acting anymore, i.e. beeing 0 for all steps. I have seen the release notes which list a lot of changes concerning magnetic field. However I cannot deduce from these notes which changes in our code are needed to have the field acting as before. I also checked the manual. The three main steps for implementing a field have not changed. Here is our code, the comented functions do not make a difference.

Blockquote
fMagField = new G4BLMagnetFields();
fFieldManager= G4TransportationManager::GetTransportationManager()->GetFieldManager();
/*
fFieldManager->SetDeltaOneStep(1e-10); // improved tracking precision
fFieldManager->SetMinimumEpsilonStep(1e-10);
fFieldManager->SetMaximumEpsilonStep(1e-10);
*/
fFieldManager->SetDetectorField(fMagField);
fFieldManager->CreateChordFinder(fMagField);
fLogicalVolumeBox->SetFieldManager(fFieldManager, true);

Thanks a lot in advance for help.
Simone