Today I found out that Apache 1.3.23 (and probably 1.3.24) has a problem 
with ELOG if used as a proxy server. Due to a bug in Apache, only one 
cookie is transmitted through the proxy at a time. This makes it impossible 
to log in into ELOG with user name and password (requires two cookies). 
Apache 1.3.23 comes with RedHat 7.3 for example.

To solve the problem, update Apache to 1.3.27.

See also http://bugs.apache.org/index.cgi/full/9655