From the OpenMPI (1.7.1) documentation:
The boolean variable MPI_WTIME_IS_GLOBAL, a predefined attribute key that indicates whether clocks are synchronized, does not have a valid value in Open MPI, as the clocks are not guaranteed to be synchronized.
It seems unlikely to me that this feature will have changed from 1.7.1 to 1.7.2 so I suspect that the answer to your question is No, OpenMPI does not provide synchronised timing across processes. An integer value of 3 supports the idea that a boolean variable does not have a valid value.