How can I increase the export resolution of marker edges in a plot?

I'm currently trying to export a plot (for a publication) and whenever I do, the border to my markers comes out looking pixelated. I'm using circle markers (e.g. 'ro') but they come out looking like hexagons.

Is there some good way to fix this?

Here is some example code that uses my exact figure formatting preferences. Also I've included a picture of what I'm talking about in the final output as well as the full file for the exported test figure.

Thanks so much for any help!

function test

    x=linspace(0,25,25);
    y=-0.01*(x.^2-25*x);

    h=figure;
    plot(x,y,'ko','MarkerSize',5,'LineWidth',0.5,'MarkerFaceColor','r','MarkerEdgeColor','k')

    title('')
    xlabel('XXX','rot',0)
    ylabel('XXX (\mu m)','rot',90)
    ylim([0,1.8])
    xlim([0,25])
    pbaspect([1,0.75,1])

    grid off
    box on

    FigFileName='TEST';

    width = 3.4;     % Width in inches
    height = 3.4;    % Height in inches
    set(gcf,'InvertHardcopy','on');

    set(gcf,'PaperUnits', 'inches');
    papersize = get(h, 'PaperSize');
    left = (papersize(1)- width)/2;
    bottom = (papersize(2)- height)/2;
    myfiguresize = [left, bottom, width, height];
    set(gcf,'PaperPosition', myfiguresize);

    set(findall(h,'type','text'),'FontSize',8)
    set(gca,'FontSize',8)
    set(gca,'FontName','Helvetica')

    set(h, 'Renderer', 'painters'); 

    PrintFigure=1;
    if PrintFigure
        print(h, '-dpdf', strcat(FigFileName,'.pdf'),'-r300');
    end
    end

%

Answer 1

[Max Monn]

I figured out that this is a problem with MATLAB 2014b on Mac OSX 10.10. I installed 2014a and everything seems to be in order.