Thanks Brian.
I moved your test script without the display part into the test/image_test.py
Committed revision 990.
Attached is a patch for image.fromstring with ARGB. Also attached is a script (not a unit test) to demonstrate the error on the trunk and confirm the fix (all 4 columns should be identical, and it shouldn't print "ERROR")
... I should say even though I am confident the fix should work well on both endian architectures, I've only tested it myself on an intel machine... so somebody ought to test it on Mac too...