I am forwarding this email to Yaws mailing list as well.
I am using R10B-8 and the yaws version is 1.48.
Was there any similar issue reported in old release?

---------- Forwarded message ----------
From: Stephen Han <kruegger@gmail.com>
Date: Thu, Sep 18, 2008 at 1:02 AM
Subject: Yaws shows high memory usage and erlang:port_info shows 'undefined'
To: - Erlang Questions <erlang-questions@erlang.org>

I am running yaws server and I am seeing the memory is increased to 500M within a week.
If I do, erlang:memory() command
I do see binary is using up that much.
While try to debug this, I just ran the command [ erlang:port_info(X) || X <- erlang:ports() ].
I do see almost 1100+ 'undefined' entries shows up. Is this normal?
Is there any relation with number of 'undefined' erlang ports and memory consumption issue?
Can anyone point where the possible issues lie?
thanks in advance...