Hi Sander,
I think it's a bug, but it may be in the import rather than the export. When I look at the pdf with Acrobat it's much better.
SetDirectory[NotebookDirectory[]];
p1 = Graphics[{Pink, Disk[{0, 0}, 5]}, Frame -> True, PlotRange -> 4,
PlotRangeClipping -> True]
Export["out.pdf", p1];
Import["out.pdf"]
But when I look at out.pdf with Acrobat or Photoshop I see this: (Converted to png for posting)
