Scriptaculous Droppables Draggables problem

I’m working on a 3 column grid of draggable objects. Draggables are
Droppable on any other Draggable, where they are placed just above after
a successful ajax call. I have all logic and ajax stuff in place.

Its kinda working, but - the interface is quite jumpy, and seems to have
a problem moving elements from left to right. Right to left is more or
less ok.
The area where it detects the droppable seems quite fragile. About 1
time in 8 I am able to actually get it to drop in the right place!

I’ve been working on it all day - If anyone has any pointers it would be
very much appreciated!! Are there any in-depth tutorials/examples on
interface building with scriptaculous drag and drop?

Thanks in a advance.