Hi, I am encountering the problem that a working child process is frozen in the middle of its work, and continues only when its parent process ( which spawned it earlier on ) calls some MPI function. The issue here is, that in order to accept client socket communication the parent process is, at the same time, performing a select() on a server socket. It expects the child to finish its work, which will be collected and processed at a later date. This now cannot happen as the child does not continue until the parent process calls Recv(), Probe() or sends something itself. Is there the possibility that some mpi daemon freezes the child process if its parent process goes to "sleep" while listening to a socket? If so, how can I avoid it? These are independent processes and even though interlinked should not influence each other in this way. Regards, Murat