Comment 9 for bug 396736

per our IRC discussion... I think the reason I'm seeing slightly different behaviour is that my application font is set to 6.5pt and notify-osd's extract_point_size() is assuming that font sizes are integers.
I really quick hack to convert that function to sscanf for %f and return a gdouble seems to work, but other than the fontconfig manual I can't conclusively prove that fractional font sizes are legal in gtk/gnome.