Since you say the refund process was completed, I assume you can see the request in the access log?
You might want to ask on the AOLserver list, because I suspect this has nothing to do with OpenACS per se but rather AOLserver->browser communication.
I know that the socket dropping during a long file transmission to a user will cause AOLserver to log a mysterious error.
I don't know offhand if a socket drop logs an error for normal ns_return type operations though. It's not unknown for dial-up connections in particular to get interrupted by, say, someone picking up a phone hooked up to the same line in a home.
But this is the type of problem I suspect. Is this on a production system or development system? Is there some sort of pattern to the IPs you see in the access log that fail?
