The attached files provide all source code needed to reproduce odd behavior in the subject.
I have AJAX loading a chunk of HTML which contains a draggable. The _placeholder_ of this chunk is inside a table cell, together with a SELECT box (right above the placeholder).
AFTER I load the AJAX, the following occurs:
goodSortable.html - I am able to drag the cross and drop it inside the dropspot, without any hacks.
badSortable.html - Only after I "disturb" the dropspot, by dragging _the dropspot_ and dropping it somewhere, then the drag & drop with the cross works.
Things to consider:
A) If the chunk in statically embedded in the DIV placeholder (i.e. no AJAX), it works on badSortable.html
B) Also, in goodSortable.html, if you set the SELECT width to something too large, it will break.
There must not be a SELECT on the same cell that the placeholder of AJAX, which would EXPAND the loaded DIV more than it's ORIGINAL WIDTH.
If this condition happens, there's no drop in dropsort without the hack described above.