Forms :: Combo Box Selecting Beyond Displayed List

I have a working combo box on a form that displays issue numbers for part number typed into a text box.This all works fine when the list of issue numbers is below the displayed list (16), but when the list is longer than 16 you cannot seem to select anything after item 16.

When the combo box has, say 25 items a scroll bar appears allowing the user to scroll down to item 25, but when you click the mouse the list just reverts back to the first 16 items? The only way to select an item after 16 is to select item 16 which then closes the combo box, then when you reopen it the list now shows items 17 to 25 which you can then select item 25.

This is the same in reverse, when you have item 25 selected, you cannot select item 1. When you click the mouse the list reverts back to items 17 - 25.The combo box is populated in code using the lost focus event on the text box for the part number.