I'm not sure that the DFP error is really an issue. The hsync and vrefresh are your problem however. Remove both of the lines that reference Hsync and VertRefresh from /etc/X11/xorg.conf, and try to startx then. It will probably start at a low res, but once you have video, you can trouble shoot from there. I'm not sure what your ranges should be for your monitor. I've never had great luck in finding that info. Check the back of your monitor, it might be written there. Also, I normally just remove the line for Hsync without any problems.