jQuery UI (1.7) seems to have a few bugs with its use of inline styles with ui.sortable.
If I define a helper, with a width and height set in CSS, the helper's properties are ignored and an inline style is set that overwrites that data for my helper. So, if my helper is 200x200px, as soon as that helper is cloned and used, an inline style is applied to make it completely different dimensions.
The only way to fix this is to define an inline style on the element.
This appears to be because it is checking helper.style.width instead of $(helper).width(), which reads the width correctly.
A similar thing happens when I explicitly define a helper, or use clone. The original item in the list gets an inline style of display: none; applied to it, even if I have defined it otherwise.
Here is a testcase:
Here is an example of it working, if I explicitly define an inline style: