iSeries Nav - Run SQL Script Error

When trying to run an SQL script fron iNav, I get a pop up exception
"The requested operation cannot be performed because the server
connection was dropped."

If I click "OK" (the only option) I get the script window but the
title bar notes that I am not connected. If I enter a script and
select run,  I get a pop up where I can log on to a server.

If I select my server and database and try to connect, I get the same
exception error.

Another devloper here can run scripts like this. I have tried using
his user id to connect from my PC and have the same problems.

I can connect to another server and run scripts but there are two
servers that always give me the same problem.

Kyle