IAdsGroup.members returns an empty set

Hi all,

I have a piece of code (see below) which is used to retrieve all
user/groups 
and their members. This works fine in many network environments, except in

this network where the code was used recently. Are there any conditions 
which cause the members property to be empty? The code DOES work for 
BUILT_IN groups like "Administrators" and "Guests", but when a custom
domain 
group is retrieved, the members property stays empty. (and this problem
only 
occurs in one particular network). Some information:

- The user is a Domain Admin
- There are custom domain groups which have other custom domain groups as
a 
member.
- All the domain groups are found in the first For Each loop.
- Only the members of the BUILT_IN groups are found in the seconde For
Each 
loop
- Normally this code works fine, so perhaps it's caused by the network 
environment
- The IAdsUser.Groups property works fine in this network (used in an
other 
piece of code)

--------------------------------------------------
Set GroupObjectArray = GetObject("WinNT://" & strDomain)
GroupObjectArray.Filter = Array("Group")

For Each GroupObject In GroupObjectArray
    //this does work for BUILT_IN domain groups and for custom domain
groups

    Set memberList = GroupObject.Members
    memberList.Filter = Array("Group")

    For Each MemberGroupObject In memberList
            //this only works for BUILT_IN domain groups. Normally this 
works fine for all groups.
            //groupObject = "BUILTIN\Administrators"
            //memberGroupObject = "domain\Domain Admins"
    Next MemberGroupObject

Next GroupObject
--------------------------------------------------

Anyone any ideas?
Thanks!