We are having an issue using the API to delete groups. Per the API docs relating to delete-contact:
The example below shows a delete-contact request. If this is the last contact in any of the groups specified in this delete-contact request, then the group will be automatically deleted.
The contacts are deleted from the group, but the empty group remains even if the user logs out and back into Jabber.
It does delete the group, but your application has to refresh the roster to see that the group doesn't exist anymore.