I am not sure what is causing the message, but I have a couple of ideas. One area that might cause an issue when enumerating the ports could be phantom adapters. Take a look at http://www.intel.com/support/network/sb/CS-029916.htm for information on how to get rid of them.
Some other registry corruption might be behind a message like that. If the registry entries are something that gets removed when you uninstall the Intel(R) Network Connections software, then removing the software and doing a clean install might help.
Another possibility is an issue between the latest teaming software and the PRO/100+ adapter, which is very old and would not be tested with the latest software.
If removing phantom adapters and a clean software installation does not help, and If you can create a team and the team seems to be functioning correctly, then I would not be overly concerned. If you want to modify the team, you might have to work around the error by removing the team and creating a new team using the new configuration you want.