Oracle Control and Webserver
As previously mentioned by @Jack Douglas, Oracle Application Server (a J2EE container) is installed. You may want to do a tcpdump to see what applications are running on conflicting ports. You can find a list of ports used by Database Control here: Managing Oracle Port Numbers.

Some ports used by Enterprise Manager Database Control:


1158 - Http Port for Oracle Enterprise Manager Console.
3938 - Oracle Management Agent.
5520 - RMI port for Enterprise Manager Console. 
5540 - JMS Port for Enterprise Manager Console.