strange behavious with AD 'domain users' group

Have been playing around with filr for a few days trying to get it to work properly

here is the current situation i'm in:

Imported all my AD users, as well as a few levels of groups so that filr knows about them all

If I check the groups section and look at my domain users group it shows as having no members, however if I view it using an LDAP browser and go into the properties and look at the member list, all the domain users show up there - note they are not explicitly listed under the 'member' attribute as multiple values, they just show up under group membership when I make a query

If I look at the memberOf attribute on the domain users group, it shows as being a member of the cn=users,cn=builtin,dc=ourdomain...

looking at that users group in the builtin shows our domain users group as being a member which seems fair enough

so the big question is, does filr have an issue with permissions that are assigned using the domain users group, or any of the other built in groups in AD, it seems that domain users is a special type of group that filr seems to have trouble getting the real list of members associated to it, is there some way that filr can be configured so that it actually retrieves the correct list so I get access to the net folders which I should have access to

the permissions on the windows share i'm trying to use are assigned using the domain users group, so because filr can't get the list of users there I get no access to the group even though I can see the appropriate files in a windows client machine

something here is not quite as it shold be it seems, i'm sure we aren't the only shop that assigns share permissions using the builtin domain users group