Upon AD Import for SharePoint, MOSS does this automatically: "Office SharePoint Server 2007 automatically adds your manager, peers, and direct reports as your colleagues". How do I disable this automatically so it's a clean list of colleagues?
The properties for the user profiles are configured from the Share Service Provider (SSP). Go to SSP > User Profile and Properties > View Profile Properties.
In this particular case (I think) the Manager property defines the direct reporting structure for manager peers etc.
To clean the data you can disable the connection from the Manager property to the Active Directory.
Eit the property using the drop down, go to the Property Import Mapping section
Set the Data source field to map to be "Not Mapped"
This should ensure that the field is not moved into your user properties.
You will have to re-import the users after the change of course.
I would recommend (if at all possible) setting up an internal process to ensure that AD is the correct source for this information so that in the future the Manager property is correctly entered.