scriptaculous drag-and-drop and fixed position drop_receiving_elements

I've got to imagine someone's run into this problem before, though I
can't seem to find a good explanation on how to fix it. Any guidance
would be greatly appreciated...

I have a fixed position div with category names in a "column" on the
left in my app. In the main body are entries, which a user can drag
onto the corresponding category in the left column to categorize the
entry through drag-and-drop. Since the list of entries scrolls, I've
made the category module fixed position so that it is always in view.

The problem is that once I start scrolling down the list of entries
and the categories module moves, it no longer accepts drag-and-drop
entries - the drop zone for the categories has been left behind at the
top of the column.

I found this related fix and tried it, but it didn't seem to do the

I replaced 'within' with 'withinIncludingScrolloffsets' in dragdrop.js
and it didn't do the trick.

Has anyone had trouble with this in the past? Any thoughts on how to
get this to work?