yes it does actually it worked with either pop-ups or pull-downs
the thing just needs to pop-up/pull down partially off screen yet have the whole menu fit on screen at one time and i see the bug.

evilPopUp uses a .gorm for the pop-up but manually added items.

try EvilPopUp

set the pop-up button in the gorm to a pull-down button
set N_POPUPITEMS to something like 25,
move it so that the thing is near the bottom of your screen,
and click the pull down

I was able to reproduce it that way.

EvilPopUp.tar.gz can be found here.

http://lists.gnu.org/archive/html/bug-gnustep/2003-04/binvx69CC2g1E.bin

there are other bugs when the entire pop-up is too big to entirely fit on screen, which is why i set it to 25...

here I can scroll down, but going to the top of the screen and dragging the mouse up, also scrolls down.

When an NSPopUpButton is clicked, the menu pops up in the wrong location. Instead of the currently selected item in the menu being positioned directly over the button, the entire menu is positioned higher on the screen by the size of one item, so that the next item down in the menu is over the button.

A possibly related issue: When popping up a menu that would extend off either the top or bottom of the screen, the menu is repositioned so that it is all on the screen. But in this case the mouse cursor position and tracking is not adjusted accordingly. So as the mouse is dragged the menu highlights an item either higher or lower in the menu than the one that the mouse is over.

Note 1: My popup buttons are loaded from a nib file, in case that is relevant.

Note 2: I added a comment to bug #15902 about this a couple weeks ago, but it didn't seem to be getting any attention so I decided to post this as a separate issue.