I noticed that on http://www.home.zonnet.nl/rareitsma/lyx/ it says to download certain TTF fonts for Windows, and if an issue pops up where horizontal or vertical lines are being hidden (e.g. in equal signs, but also happens with +/-, epsilon, and a whole bunch of stuff), to tweak the font size. [I think this issue only happens with ClearType or no text smoothing, but I could be wrong]. I found an easier solution: uninstall the old fonts if you have them, and download Mozilla's math font collection from http://www.mozilla.org/projects/mathml/fonts/. These will look good on Windows at all zoom levels. Maybe someone can add this to the Wiki and install instructions as well.
Matei Zaharia
