xboard crashes Xvfb

[Phil Dybvig]

  Is anyone knowledgeable about Xvfb?  Here is how to reproduce the problem I 
have:
  
Xvfb :1
export DISPLAY=:1
xboard

Running xboard crashes the X virtual frame buffer with the message:*

  No copyPlane proc registered for depth 4

  I also tried running Xvfb with -pixdepths 4 which didn't help.  Some other
programs (xterm, gimp, and display) did not crash Xvfb.  I tried some explicit 
screen definitions (e.g. -screen 0 1600x1200x4 or 12080x1024x4) but this only 
changed the number at the end of the error message.  This seems like pretty 
basic use of Xvfb and worked fine for me before in Solaris.  Currently I am 
running FC2 with the 2.6.6-1.435.2.3 kernel, xboard-4.2.7-3, and 
xorg-x11-Xvfb-6.7.0-5.  I don't think the hardware and softare versions matter 
so much because I have the same message on an i386 laptop running redhat 7.3.
  
  Background:  I run a chess program (crafty) using the xboard (zippy) interface 
that allows it to play automatically on the internet chess club (icc).  I want 
to run this in the background on a machine that will not always have X running.  
In the past, I used Xvfb (X virtual frame buffer) to have it run in its own 
sandbox so xboard can think it is connected through X to a monitor.  However, 
the same configuration doesn't work.  It is a little hard isolating the problem, 
because the hardware (SUN Sparc to Intel), OS (Solaris to linux) and versions of 
all the programs have changed.

-- Phil

*There are additional error messages when Xvfb runs, about a font not being 
found and also several about IPV6 (which I have turned off but Xvfb doesn't 
know).  However, I have reason to believe they are not the source of the 
problem.