If two threads in same application use QValueSpaceSubcriber or QValueSpacePublisher to access the same cenrep uid, the second of those threads will panic.

QtMobility PublishSubscribe settings layers are implemented as globals. That means that there is only one instance of the layer, and that is shared between all threads in the application.

Symbian Settings Layer uses the native Symbian CRepository API for accessing the central repository. CRepository instances can't be shared between threads (if the class is used from a different thread than where it was created, it will panic in the client-server communication).

A new CRepository instance is created for each different repository UID, but after that the same CRepository instance is always used for accessing that repository. So program that tries to access same repository from two different threads will crash. Even if the program uses separate QValueSpaceSubscriber instances, the Symbian settings layer backend is still shared between those instances.

This is a pretty serious limitation, because there is no easy workaround for this problem.