Since the dawn of the Glasgow cluster we have been cursed with a low level of globus 79 errors. We did not understand these well, but always believed that they were caused by a confusion in the gatekeeper, where the X509 authentication seemed to suffer a race condition and get muddled between users.
However, since upgrading to an SL4 CE and installing it on a different machine we still get these cropping up (an example).
The GOC Wiki suggests this can be caused by firewall trouble or an incorrect GLOBUS_TCP_PORT_RANGE. Now, this is (and was) correctly defined on both machines to be the standard 20000-25000. However, I have decided to change it to 50000-55000 in case we are tripping some generic nasty filter somewhere else on campus.
Since I did that, last night, we haven't had a 79 error - however this proves nothing so far as we can easily go for a week without one of these happening.
I also contacted the campus networking people to ask if there was any known port blocks in this range.