How to allow users to customize groups?

I have a setup where I have users organized into various groups, with contact list sharing enabled. However, some of my users would prefer to organize their contacts differently than the default. They can customize their groups on their local Jabber client, however the next time they login, everyone is moved back to the default group setup. Is there a way to allow users to customize their groups and have the changes saved between sessions? I am running Openfire 3.4.5.

The users should be able to create custom groups. You then copy the the users to the custom groups. If they name the groups with a preceding * then the groups will show at the top of the list. This should hold between sessions. It is important to note you are not moving the people out of the orioginal groups you are copying them. Shared groups can not be altered and save by users.

Thanks, that got us pointed in the right direction. My users were able to setup their custom groups by adding the buddies to their list again and hiding the default group in their list.