I've reproduced this on Chrome and Safari (most up-to-date versions as of now) on my Mac:

In this example: ​http://jqueryui.com/demos/sortable/#connect-lists

Take one element from the first list and move it straight down, then across and place it as the last element into the new list. If you do this without hovering over an element in the second list then you will not be able to place that element. However, if you moved over any element in the target list then you can in fact place the element at the bottom of the list.

Given the simplicity of the demos (hard to get something wrong there), I thought it better to put this into the ui.droppable category rather than the ui.demos category, but feel free to move the ticket if I misplaced it.

In the Themeroller: ​http://jqueryui.com/themeroller/

Under Font Settings > "Family" enter in the value:

'Helvetica Neue',Arial,sans-serif

This works as intended, and the CSS/text on screen updates properly.

Now download the Theme. The css output ends up looking something like this:

/* Component containers
----------------------------------*/
.ui-widget { font-family: \\\\\\\\\\\\\\\'Helvetica Neue\\\\\\\\\\\\\\\',Arial,sans-serif; font-size: 1.1em; }

Which is invalid CSS.

When the dialog has a long title it will appear behind the close link at the top right. I suggest a "padding-right:30px;" when there's a close link on the dialog.