Spinning cursor in "display dialog" in Perform AppleScript 
I'm using FMPA 11.0.3 on Mac OS X 10.6.8. In many of my scripts, dialog boxes are shown. Since AppleScript offers more flexibility with dialog boxes than FM's Show Custom Dialog (icons, automatic sizing, ...), I often use a Perform AppleScript [ display dialog "A" with title "B" with icon ... ] command to show the dialog. This works fine if called at the beginning of the FM script, but not so much otherwise. The usual mouse pointer is often replaced by the colored spinning wait cursor known to appear on a Mac when a program is busy. The buttons can still be clicked and everything, it's just very confusing for the users of my runtime solution, and I'd like to get rid of it if at all possible.
The issue has been discussed at http://fmforums.com/forum/topic/68891-applescript-spinning-wait-cursor-and-delay-when-running-the-first-time already in late 2009, but the workaround that is given there, namely adding a Refresh Window  command before the AppleScript, doesn't seem to work in my case.
Perhaps an FM official could explain what exactly causes the spinning cursor and how it can be worked around. Any help from others is also highly appreciated, of course.