So how to make it work. Download Soap UI 3.6 (or 3.6 beta 2), and it will work fine until you find out this nasty bug. You can’t change the address of the endpoint of a request you are trying to change! Very Annoying! But there’s a work around I came across looking at this forum post - http://www.soapui.org/forum/viewtopic.php?t=2293
The work around is – Click on the drop down, click your mouse somewhere else and release it on the option you actually want to click and that should do it. I would’ve never figured this out for myself. Hope soap UI can iron out the mac issues, as it’s a great, great tool.