Print preview broken in OS X

Call the "Print Preview" from eg. Assistant or from the "Text Edit" Qt demo.

1) in both cases, there is no close button (unlike under Windows), no apparent way to cancel/close this window. The first time this has happened, I had to force-quit the application. Then I found there is a way to exit the window, which is:
from this window, open the Print dialog, and from it, press the Preview button... this closes the Preview window! Certainly not the right way to do things!

2) The "Text Edit" demo "Print Preview" shows nothing (no problem under Windows).