Not sortable if wrapped in another li tag

[Cartman34]

Hi,

First, thanks for this great plugin.

Then, the title is very explicit, this plugin is not working if we use a ul/li list in another li tag.
The items (li) are selectable but not sortable. And if we use it with the original sortable plugin only, it works.

I'm testing with the last version from the given jQuery & jQuery UI files.
I tried with my own recent files (resp. 1.10.10 and 1.10.3).

My solution is to specify the items option using a class that any parent does not match like "li.file".
This is working well but the fact is that plugin has a problem with wrapping li tags.

Here is the fiddle with all tests:
http://jsfiddle.net/Loenix34/h2KrX/5/