If I create a circular reference purposely, the circular reference
toolbar does not appear and no warning is displayed.

The "Formula Auditing" toolbar's Evaluate Formula button correctly
identifies the circular reference, but when I force the "Circular
Reference" toolbar out of hiding (customise, etcetera), the "Navigate
Circular Reference" combo box is empty. It remains empty even when I
select or activate the cell containing the circular reference.

The reference needn't be anything complex.
E.G.
A1 = A2
A2 = A1

Iterations are working. EG 500 iterations increases the values by 1000

Automatic calculation is also working fine.

Excel 2002 SP3.

How can I get the Circular Reference toolbar to function correctly?