membershipId returned from group member search endpoint is different

the url : http://www.bungie.net/Platform/Group/' . $groupid . '/MembersV3/?currentPage=1&itemsPerPage=50' section of response: "user": { "membershipId": "[b]9337328[/b]", "uniqueName": "9337328", "displayName": "Haktar", "profilePicture": 0, "profileTheme": 0, "userTitle": 0, "successMessageFlags": "0", "isDeleted": false, "about": "", "firstAccess": "2015-01-04T21:26:49.42Z", "lastUpdate": "2015-09-23T00:50:28.537Z", "xboxDisplayName": "Haktar", "showActivity": true, "followerCount": 36, "followingUserCount": 31, "locale": "en", "localeInheritDefault": true, "showGroupMessaging": true, "profilePicturePath": "/img/profile/avatars/default_avatar.gif", "profileThemeName": "septagon", "userTitleDisplay": "Newbie", "statusText": "", "statusDate": "0001-01-01T00:00:00Z" } The problem I'm having is the membershipId that is returned from a group member search ([b]9337328[/b]) is different from the mebmershipId returned from /GetMembershipIdByDisplayName/ which is [b]4611686018444912810[/b], the later number is the one i need, i can only assume the other number is the group membership id and not the account id, is there anyway to retrieve the account membership id from a group member search? if not i had planned on looping through a /GetMembershipIdByDisplayName/ for each group member but it seems wateful and nor every member has there gamer tag linked :( a point in the right direction would be really appreciated, I've figured out most but a nice solution for this is escaping me