Even though this thread has derailed, just to finish the PAL discussion here's an article to read: http://en.wikipedia.org/wiki/576i
Just like Laserschwert says, 720x576 is what it is and wasn't "designed for display at 1024x768 square pixels". In the case of square pixel aspect ratio, 720x576 is 5:4 while 1024x768 is 4:3 so nope, they don't match and back when TVs and broadcast signals were launched, they didn't use resolutions like 1024x768.