This is a vanilla implementation from the CDN, developing on localhost.
I cannot seem to find a consistent way to replicate it, but it seems to happen most while dragging items near the bottom of the list. The dragging tool-tip does not lock to the mouse, but rather gets appended to the bottom of the document, where is will not go away.

This persistent tool-tip reacts to continued attempts to use the dnd.

I checked the error in fire-bug ie and chrome consoles and it always returns the same thing:
Chrome:
Uncaught TypeError: Cannot read property 'type' of undefined Source.xd.js:8
Firebug:
_a.getItem(_b[i].id) is undefined
window[(typeof (djConfig)!="undefined"..._4.dnd.AutoSource(_3d,_3c);}});}}};}); Source.xd.js (line 8)
IE’s was not nearly as helpful.
Please help folks! I created a stripped down version of my page in jsfiddle here: http://jsfiddle.net/ykNJ8/
I tested it and the error does occur in fiddle.
Heh, took me forever but I figured out your problem. The problem is that you are instantiating two dojo.dnd.Source’s.
The first: When you specify the dojoType attribute on your id=’faq’ div.
The second: When you are calling new dojo.dnd.Source(sortID).
The result is that you have constructed two widgets on the same div and they are fighting with each other.
Here’s a fiddle that fixes the problem by only using the markup-driven widget:
http://jsfiddle.net/TtbPh/1/
Don’t give up on Dojo widgets just yet! There is a fairly steep learning curve, but once you get it nailed down you’ll wonder how you ever lived without them 🙂