Membership Tables Empty After Create Users

I had to upgrade a sites ecuroty from a custom system to .net membership. I created all the users like this.

ds = Wservices.SelectBulkUsers()
If Not ds Is Nothing AndAlso Not ds.Tables(0) Is Nothing AndAlso ds.Tables(0).Rows.Count > 0 Then
For Each dr In ds.Tables(0).Rows
username = dr("username")
password = dr("password")
role = dr("SecurityClearance")
email = dr("email")
Dim newUser As MembershipUser = Membership.CreateUser(username, password, email, "", "", True, status)
Select Case role
Case "1"
Roles.AddUserToRole(username, "normal user")
Case "2"
Roles.AddUserToRole(username, "administrator")
Case "3"
Roles.AddUserToRole(username, "super administrator")
End Select
If newUser Is Nothing Then
errorMsg = username & " - " & status.ToString & "<br />"
End If
Next
litResult.Text = errorMsg
End If

I thought everything was fine and then went through the labourious task of replacing all the usersids used a as a foreign key in all the tables. It was only after doing this and trying to log on I couldnt, and noticed the membership table was empty. I assumed (stupidly) as it had done the users/ roles it must have done the membership. As I have already re-assigned the old user ids I dont want to import again as the userid will chnage. So my question is: Can I create a membership for each of the users in my aspnet_users table? I have the passwords etc in varchar fields at min from old table.