Why are Minor Ticks Resorting to Background when Printed to File?

I am having a problem with the minor ticks on both axes resorting to the background when I print to file. This happens regardless of the renderer or the exported format. The minor ticks are there when I create the figure, but move to the background after printing to file. The major ticks do remain in the foreground. Matlab ver. 7.9.1 on a Mac Pro desktop.

Here's my code:

if true
  % code
end
%
H = figure(1)
set(H,'PaperPositionMode','auto')
set(H,'Renderer','zbuffer')
%%%%set(H,'Renderer','OpenGL')
set(H,'Position',[400 1067 1400 1067])
%
semilogy(latArray(1),plxPlot(1))
hold on
pcolor(latArray,plxPlot,zonalVar2)
vInt = 10:15:max(max(zonalVar2));
[c,h] = contour(latArray,plxPlot,zonalVar2,vInt,'w','LineWidth',1);
%
axis([latArray(1) latArray(end) min(min(plxPlot)) max(max(plxPlot))])
axis ij
shading interp
colorbar
set(gca,'XTickMode','manual')
set(gca,'YTickMode','manual')
set(gca,'XTick',xplot)
set(gca,'XMinorTick','on','YMinorTick','on')
set(gca,'TickDir','in')
box on
set(gca,'layer','top')
set(gcf,'InvertHardCopy','off')
% 
xlabel('xlabel')
ylabel('log_{10} ylabel')
title(['title'])
%
print(H,'djpeg100','filename.jpg')

Anyone have any ideas, or is this a bug? Thanks!!