Delphi does not see MS SQl indices

Hi everyone,

In Delphi, I'm using simple MS SQL table with a primary key.
The problem is, Delphi sometimes sees no indices:
On some tables, if I try a Findkey, I get the message 'No index active'.
On others, it works fine.

The differences are:

                  Working ones      Not working ones
                  ---------------   ----------------
Table created     Manually in MMC   With Borland datapump
Index name        PK_tablename      Tablename0

If I dump the script for the database:
The working ones are created like:

   CREATE TABLE [dbo].[AFW] (
    [WerkgeverID] [char] (5) NOT NULL ,
    [InstellingID] [char] (4) NOT NULL ,
    [FormulierID] [int] NOT NULL ,
    [MutatieTeller] [int] NOT NULL ,
    [Tick] [bit] NOT NULL
   ) ON [PRIMARY]

   ALTER TABLE [dbo].[AFW] WITH NOCHECK ADD
    CONSTRAINT [DF_AFW_WerkgeverID] DEFAULT ('') FOR [WerkgeverID],
    CONSTRAINT [DF_AFW_InstellingID] DEFAULT ('') FOR [InstellingID],
    CONSTRAINT [DF_AFW_FormulierID] DEFAULT (0) FOR [FormulierID],
    CONSTRAINT [DF_AFW_AantMaalVerstuurd] DEFAULT (0) FOR [MutatieTeller],
(**)
    CONSTRAINT [DF_AFW_Tick] DEFAULT (0) FOR [Tick],
    CONSTRAINT [PK_AFW] PRIMARY KEY  NONCLUSTERED
    (
     [WerkgeverID],
     [InstellingID],
     [FormulierID],
     [MutatieTeller]
    )  ON [PRIMARY]

The non-working ones are created like:

   CREATE TABLE [dbo].[TbBurgSt] (
    [Burgerlijke_staat] [varchar] (20) NULL
   ) ON [PRIMARY]

   CREATE UNIQUE INDEX [TbBurgSt0] ON [dbo].[TbBurgSt]([Burgerlijke_staat])
ON [PRIMARY]

There are differences, but which one do I need to change to have Delphi see
the primary index?

Thanks,
Jan

NB:
The line marked (**) is obviously the result of the field being renamed
later, isn't it?