After many weeks of running tests on different systems, all started from inside the same X session and using ssh -X forwarding to make the display accessible from the systems running the tests, X forwarding just sorta stops working. The remote machines still get a localhost:N DISPLAY variable established, but trying to actually run an X client results in connection errors. Does this sound familiar to anyone? Is there some resource that could be "used up" on the host machine if some of the test sessions terminate abnormally so that eventually there isn't any left to make forwarding work? It isn't the X session itself that has problems. If I talk to it directly without using X forwarding, it works fine. It is just the X forwarded connections that stop. Rebooting the host system makes everything work fine again for a few weeks, then the X forwarded connections stop working again. Details: Host system is fedora 13 x86_64 running openssh-server-5.4p1-3.fc13.x86_64. The X display the tests are run from is a VNC server.