I'm trying to activate LDAP login to the mobile server but not yet succeeding

We have set up dedicate user and an appropriate security group on the LDAP server. Unfortunately when I try to login I get a failure to match a username to the specified group with the error message;

2014-06-13T09:53:18.144+0100 WARN [omniscope.service.mobilewebserver.server] - User bfromson successfully logged in active directory, however it cannot be found in this group: CN=Security Omniscope Users,OU=Security,OU=Global Groups,OU=London - 2 Gresham Street,OU=[Root],DC=uk,DC=corp,DC=investec,DC=com

while this looked at least partially promising as it appears that communication is occuring with the lDAP server I then tried another non existent userid and got the same message:

2014-06-13T09:53:31.832+0100 WARN [omniscope.service.mobilewebserver.server] - User invaliduser successfully logged in active directory, however it cannot be found in this group: CN=Security Omniscope Users,OU=Security,OU=Global Groups,OU=London - 2 Gresham Street,OU=[Root],DC=uk,DC=corp,DC=investec,DC=com

which suggests that the "successfully logged in active directory" part of the message may not mean the userid has been validated.

I can send you the folder.xml file separately if that would help.

Thanks.