Hhierarchical servicegroups displays double servicegroups

Having 4 levels of servicegroups some members are mentioned double.

The service ‘http’ on host forum01, is part of servicegroup ‘apache’.
This servicegroup is part of servicegroup ‘HTTP’,
which is in turn part of servicegroup ‘web’,
which is in turn part of servicegroup ‘domainname’

the service http for host forum01 is displayed 5 times in the servicegroup (web) status.cgi.
In the HTTP servicegroup status.cgi it displays 3 times.

[attachment=0]double http.png[/attachment]

This happens with dozens of services.
Anyone has a solution?

Regards
Donald