UNUSUAL MOUSE SCROLL BEHAVIOUR

[MARK]

I have 2 forms both with a combo box. The selection within the combo
box is based on a statement each:

SELECT * FROM dbo_consumables ORDER BY [type];

&

SELECT DISTINCT [CONSUMABLE_CODE] FROM dbo_consumables ORDER BY
[CONSUMABLE_CODE];

(not sure if relevant but just illustrating)

The selection then changes a subform to show relelvant records.

There are no 'event procedures' listed for the properties of either
combo box or subsequently the form properties.

Strangely on one form when i select the drop down list, i can scroll
though quite happily with the wheel on the mouse through the list of
records HOWEVER on the second form when i engage the mouse the drop
down list dissappears back to an unselected state (ie no scroll
window).

This is very odd but i cannot find a reason why on one form it works
ok and on the other it does not?

Any thoughts?

Mark