This is very strange behavior. Could you please provide some more details – what data source are you using and how do you apply binding? is this browser specific or it happens in different browsers? A working sample, reproducing the issue would be very helpful. Any additional information will be of help, too. Thank you.
I seem to be able to reproduce this issue somehwat consistently, but it is difficult to explain.
It usually occurs when dragging and attempting to drop a node between two nodes that are subnodes of a sibling of the node being dragged and dropped.
This is hard to explain, but it occurs when in the attached screenshot when I try to drag the "1. Certification" node and drop it between the nodes as shown by the arrows.
I have tried it in IE 9 and in Firefox, and the result is the same. It is the same jscript error as noted in my first posting.
Please let me know if there is anything specific you'd like from me to help chase this down, I know it isn't much to go on.
At least now I can reproduce it at will, so that should help.
Oh, and I am using infragistics version 12.1.20121.2072.