vncserver and wrong xinitrc permissions

[Marco De Vitis <starless@spin.it>]

Hi,
I installed the vnc4server package on Etch. When launching vncserver, I 
want to get a "normal" desktop environment, so I uncommented the two 
lines in the ~/.vnc/xstartup file which is automatically created:

  # Uncomment the following two lines for normal desktop:
  unset SESSION_MANAGER
  exec /etc/X11/xinit/xinitrc

But anyway, all I got was the typical grey screen with the X mouse pointer.
I looked at the vncserver log, and the error reported was:

/username/.vnc/xstartup: line 5: /etc/X11/xinit/xinitrc: Permission denied
/username/.vnc/xstartup: line 5: exec: /etc/X11/xinit/xinitrc: cannot 
execute: Success

Indeed, the /etc/X11/xinit/xinitrc file did not have any executable bit 
set by default. I did a "chmod +x" on it, and now vncserver works fine.

What I'm wondering now is:

1. How is it that I also have a Sarge machine where the same file is NOT 
executable, and vncserver works fine anyway? The xinitrc file is called 
from ~/.vnc/xstartup exactly like in Etch, but of course vncserver is 
version 3 instead of 4.

2. is it a bad thing having an executable xinitrc?

Any ideas?
Thanks.

--
Ciao,
  Marco.