problem with LookupAccountName

Hi All,

We are using LookupAccountNameW to get first size and later SID for groups

where a user is memberof. If user is member of a group(let's call it

TestGroup) where 'Pre-Windows 2000' name is different from 'Group Name', then

mapping between sids and group's names has became somehow broken. At least

LookupAccountNameW cannot any more found appropriate SID even for other

groups, for example for group "Domain Users". If I change the name of

TestGroup group so that names in 'Pre-Windows 2000' became the same as 'Group

Name' mapping works ok for all groups. The same trouble happens if group

"Domain Users" is added to "Pre-Windows 2000 Compatible Access", after that I

cannot find mapping for groups any more.

If somebody could explain - what is wrong here? And what should I do to

prevent mapping from being broken.

Thanks in advance,

--Christine