Try this. Look at the circular flat end on both of them. On the yellow, it's a perfectly flat/smooth circle. However, on the blue (sliced) one, it's got lines running through the flat surface. Which is, actually, what I'm seeing in the actual prints, too.

I understand this is a function of the slicer, but I don't see why it can't get a smooth surface.

Here's some pics from the same angle.

cap1.JPGcap2.JPG