I'm reposting this - my first attempt appeared to get lost.  Being a
newbie I can not rule out incompetence!
What might the reason be for a significant drop in performance for
blitting objects to the screen using pygame versions 1.6 and 1.7, both
with Python 2.4.4.  We blit two surfaces, each approximately 900  x 900
pixels in size, consecutively to the screen.  Using pygame 1.6 this took
about 0.016 seconds but in pygame 1.7 it took about 0.024 seconds.  Can
anyone help?  I had thought that new versions improved performance not
degraded it.  The code is identical in both cases.