jQuery Datepicker intermittently does not display in Safari

jQuery 1.6.2 and UI 1.8.14 from Google ajax CDN. Safari 5.0.5 (Windows7) and iPad2.

I've spent the whole day trying to pin down this issue and for the most part I thought it was my code but it seems to be a bug with jQuery UI. I'm loading the the datepicker inline in Safari (Windows7) and intermittently the datepicker does not show. I used the Safari web inspector to see that the div has a height of 0px and I can see the elements as they should be within the containing div - changing the div height does not make a difference, nothing is shown. This happens only in Safari all other browsers are fine. I can also see the same issue on my iPad2, so it's not machine specific.

I've tried this using a combination of:

• jQuery 1.5.2
• jQuery 1.6.2
• UI 1.8.4
• UI 1.8.14

I get the same issue for all.

Demo: http://www.toughtomato.com/datepicker_test.php

Steps to repoduce:

• use Safari browser and open the url location above
• refresh the page a number of times until the calendar does not appear.