Installing the Sun Alert Patch Cluster will do the trick.
As the thread live as long as your executable is running, maybe it's only your external executable which is hanging.
You should try to find the parameters passed to your executable and try to launch it manually.
Is stdout and stderr from the process being consumed? You might be looking at the results of a full buffer.
You can test this by adding output redirection to a tempfile for the command that is spawned.