When I fired up the Mac I thought I saw the same thing - however, when I put my cursor in the area where the Detach icon sets, I was able to move it around.
I suspect that the problem has to do with the way Safari 4 is sizing the trade window, causing some of the info to "hide" behind other stuff. We'll take a look at it, but in the meantime you should be able to detach, use and move the window as designed.
Please write to us directly at support@hsx.com if you still encounter problems.