Thought I'd blog some of my setup problems and their solutions here:
1) Problem : No connection from new aggregator to RBNserver.
Solution : In the setup menu in cw skimmer under the "Telnet" tab, "Allow SKIMMER commands" check box must be ticked.
2) Problem : No connection to local user on port 7550.
Solution : The aggregator application must be located in an unprotected area on the c: drive. I run Windows Vista and had the aggregator application in the same director as skimmer under the program files directory. It wasn't until I moved the aggregator application to a folder directly under the c: drive that I was able to connect as a local user on port 7550.
Hopefully these tips will help someone else trying to contribute to the RBN collective.