In Ubuntu's LibreOffice, one can also reproduce this issue with KDE's Okular, and also by exporting to EPS first, and then using epstopdf to obtain a PDF file. So it seems to be something in the way LibreOffice generates the plot (EPS, PDF), that is not visible in EPS or some PDF viewers, but it is shown (or triggers a bug) in other PDF viewers.
LibreOffice 3.3.4
OOO330m19 (Build:401)
tag libreoffice-3.3.3.1, Ubuntu package 1:3.3.4-0ubuntu1
In Ubuntu's LibreOffice, one can also reproduce this issue with KDE's Okular, and also by exporting to EPS first, and then using epstopdf to obtain a PDF file. So it seems to be something in the way LibreOffice generates the plot (EPS, PDF), that is not visible in EPS or some PDF viewers, but it is shown (or triggers a bug) in other PDF viewers.
LibreOffice 3.3.4 3.3.3.1, Ubuntu package 1:3.3.4-0ubuntu1
OOO330m19 (Build:401)
tag libreoffice-