First, you should post the proxy section of the Apache configuration file here in this thread, so that we can see what the config is.
Second, I would check /etc/hosts to be sure that the hostname you are trying to reach is always known to the OS. If there is a temporary error in DNS then the proxy machine will not be able to reach the server.
That is, if the AOLserver is running on example.myserver.com with an IP of 192.168.1.1 , then add to /etc/hosts this line:
192.168.1.1 example.myserver.com
Third I would check the aolserver log to see if there is an error message there, that corresponds to the time of the apache log entry.
You may need to set certain options, like changing whether HTTP 1.0 or 1.1 headers are sent, check the KeepAlive setting, whether HTTP pipelining is enabled, etc. on the Apache proxy module. But the above is what I would examine first.
