.xinitrc not running on MacOSX 10.2.3

Friends; my .xinitrc doesn't seem to want to run on OSX when I manually 
start X.  While I usually use OrobosX, which bypasses the .xinitrc file 
anyway, I occasionally want to start it manually to launch a different 
window system (gnome) or launch it for XDMCP sessions.

How can I tell if this file is being executed at startup (of X)?  when 
my X starts up, I get the grey screen and X cursor, and nothing else; 
the xterms etc in my (totally stock) .xinitrc file don't seem to run.  
I have deleted this file and let it try to use the default, still no 
help.  I have copied a fresh file to my home dir and chmod 777 the 
file, no help.

X runs perfectly fine, otherwise, in both rooted and rootless mode.  
This is all on top (or in parallel if you prefer) of the OSX Quartz 
windowing system.

Any tips?

thanks