If I draw a simple rectangle in Paint and print straight from Paint = smooth sharp lines.
If I save that rectangle as a PNG, open the PNG and print from there = smooth sharp lines.
If I do Insert > Pictures > Select the PNG and it gets added to a new Powerpoint slide... When I print I get a blurry image and looking closely at the lines they have a sawtooth edge. I'm not resizing the image after inserting it. What is going on?

Here's a picture of what's happening. http://imgur.com/05x2Z37

I've tried 'Do not compress images in file' by the way, along with many MANY other things over several hours. What is happening to my work?