I have frequently installed xfce on both linux and freebsd machines, but something thathappens frequently is that the resolution of the display is not detected correctly. For instance on a 22 inch screen, the display is still 800x600 pixels. Similar things happen for 20 inch displays. The preferences options do not give me the choice to increase the resolution as a result of which the entire desktop looks far too much zoomed in, so to say. Where do I start to look to correct this?