X startup errors

[Richard Weil <rcweil@nyct.net>]

Where are errors in XFree86's start-up logged?  At boot I get the
message:

Checking for valid XFree86 server configuration ... error in
configuration file

This then prevents xdm from starting.  I'd like to see what part of my
XF86Config file is causing the problem if possible.  Thanks.

Richard