The output from your log indicates it is using the standard XFree NV module. Check to see that you don't have 2 configuration files (/etc/X11/XF86Config*).
XF86Config-4 is not preferred and XF86Config is the default that is used in Xfree 4.3.0.
I suspect that you have both XF86Config and XF86Config-4 files and that you are making changes to XF86Config-4 which aren't being used.
See if that doesn't solve your problem.