.NET logn issue with Crystal

When running my Crystal Report from my app, I had an issue with a login screen poping up before my report would open. I used this code to solve the problem:

VB Code:

'get userid/password to access DB
        Dim tbl As CrystalDecisions.CrystalReports.Engine.Table
        For Each tbl In rpt.Database.Tables
            Dim tbllogin As New CrystalDecisions.Shared.TableLogOnInfo()
            tbllogin.ConnectionInfo.UserID = LogonInfo.Mx_Logon
            tbllogin.ConnectionInfo.Password = LogonInfo.Mx_Password
            tbl.ApplyLogOnInfo(tbllogin)
        Next

but this only solved the problem in XP. NT still askes for a login screen...any suggestions?