When comboboxes are embedded in a JTable component (jdk-abigail, swing-pre-1.0), the behavior of the comboboxes is as follows (under Motif and under Windows):

When mouse button is clicked and released on combobox cell, the combobox pulldown is drawn. The behaviors are:

IF the combobox does not extend past the bottom of the JTable component and a selection is made from the pulldown, the list disappears and the cell that lies directly beneath the selection from the list is selected instead, as if the list was not even there.

IF the combobox DOES extend past the bottom of the JTable component (either extending past the frame the component is in, or extending past the end of the component itself) then the combobox works as expected - under motif - allowing the user to click once to see the combobox list and then to click again to make a selection from the list.

When mouse button is clicked and HELD on a cell containing a combobox, the component works properly and list selection is correctly rendered.