I just upgraded to 6.1 and when using the Frost Theme it looks like the problem in the Safari browser that moves the calendar down and hides the user icons on the User Administration page is back. I had to add a missing </div> in the adduserform.tpl to fix the problem. I found it by comparing the standard adduserform.tpl with the frost adduserform.tpl
Here was Philipp's comment on the fix for this in 6.0.
by Philipp on 08.07.2009, 14:35
The bug has been spotted in adduserform.tpl
It has now been fixed. You can find a fixed version of the file in our SVN: http://collabtiv.googlecode.com/svn-his
Just replace the one in /templates/standard/ with it and you should be fine in Safari4