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
trick:

http://dev.rubyonrails.org/ticket/6411#comment:2

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?

Thanks,
-A