I have done a little research.  This seems to be a widespread problem.
It appears on redhat lists and centos lists and bugzilla.

The most useful thing I found is 
https://www.redhat.com/archives/fedora-selinux-list/2005-
October/msg00114.html

Following the suggestions there I downloaded 
policycoreutils-1.18.1-4.9.i386.rpm and
selinux-policy-targeted-1.17.30-2.120.noarch.rpm

from 

ftp://people.redhat.com/dwalsh/SELinux/RHEL4/u3/

This seems to have fixed the problem. However, I note that the SL team
have made some modifications to selinux-policy-targeted which, of
course, won't be in this version.  I don't think these changes are
relevant for me, but YMMV.


On Sat, 2005-12-03 at 18:35 -0600, John Franks wrote:
> I am getting the following error message about every 2  minutes since
> upgrading to 4.2.  Also usb drives are not automatically mounted and
> displayed on the desktop when inserted.  Both of these problems cease if
> I stop using selinux.  
> 
> Shutting down auditd and rebooting with audit=0 does not help.
> 
> Any suggestions?
> 
> -----------------------------------------------------------
> Dec  3 17:31:44 hopf dbus: Can't send to audit system: USER_AVC 
> pid=2536 uid=81 loginuid=-1 message=avc:  denied  { send_msg } 
> for  scontext=user_u:system_r:unconfined_t tcontext=user_u:system_r:initrc_t 
> tclass=dbus