I agree that security measures could be the cause. I could not get help from the local admin until I convinced them to let me try an experiment at the server. While there, I noticed a McAffe HIPS console with lots of funny red words that said attack. The admin said that had been going on for months but they couldn't do anything about it. I nearly fainted. I cajoled them to contact admins that were upstream to put an exception in place. It works fine now.