I had the same problem when I installed the patch, (and also before the beta one; I posted about it in "1.01beta bugs: font size - 1/17/2008"). The solution is to uninstall all and then reinstall game and then the patch. Now it works.
Thanks vinboni, it worked to un-install and re-install the game.
Marshall, the DPI was set to 96. Could the problem be connected with the beta version of the patch followed by installing the official patch ontop?