After exporting and viewing a slideshow in the QuickTime format, you may find you can't maximize the player window for better viewing without getting blurred images and sometimes shakey transitions.  And some QuickTime Players default to playing the movie "full screen" which creats this issue.

One of QuickTime Player's "features" is that for best viewing, you should play the movie at the "actual" size (under the view menu). This will be the same size that you created the movie in ProSelect.

QUICKTIME PRO

Rather than maximizing it to fill the screen, use "Present Movie" (under the View Menu - in Quicktime Pro version only) as this will play the movie at exact size (eg 800x600 or 1024x768) with the rest of the screen filled with black.