Losing class when using jquery reorder

When I use jquery’s sortable functionality - when an item is moved, the one which is “shoved” out of the way or sometimes the above it, looses any class names I have attached to it.

I’ve tried a few hacks to try and get them back, none of which seem to help.

I was wondering if there was a way to switch this of, as whilst it removes them, it adds a jquery ui class?

The code ive used is the example on the jquery site, I just have my own styles attached to the li items. (ive attached a before and after of the list items)

<li class="project high ui-droppable" priority="high" projectid="5"><h1>This Is A Test Project 5</h1></li>

<li class="project ui-droppable" priority="high" projectid="5" style=""><h1>This Is A Test Project 5</h1></li>

a sandbox version of the problem can be seen here
comos - project management system

thanks in advance =)

Pretty odd, but an ajax request to a processor.php takes place after I move the first block after block #3:
action=update&t=projects&project=3&prio=undefined
Then it loses the class…