Logging into Sage Line 50 from Delphi

[StevenK]

I'm attempting to log on to Sage Line 50 data through Delphi. I'm using the following syntax :

tpUserName := edit1.text;
tpPassword := edit2.text;
TRY
// Create Instance of Engine and Workspace
SDO := CreateOLEObject('SDOEngine.8');
WS := SDO.Workspaces.Add('MyConnection');
// Connect to Data Files
WS.Connect(szDataPath, tpUserName, tpPassword, 'ThisIsUnique');
EXCEPT
MessageDlg('Unable to connect to Sage', MtWarning, [MbOK], 0);
Exit;
END;

I've set up a number of users in Sage but can only log on through Delphi using the 'manager' username and a password of blank.
I've set up users, i.e. 'User1', 'User2', etc. (with passwords the same) but I seem to be unable to log in using them through Delphi - I get the returned message that the user-name/password are not valid. However the log-ins do work fine when using Sage directly.
The Sage Developer help files indicate that 'the Line 50 Access Rights option is switched on' which it is but I still am unable to achieve my aim.
Anyone have any answer to this ?
Thanks in advance.
Steve