'Unable to read from thread kernel pipe' error in Apache

[Will McCutcheon]

I have a server running 5.2.1-RELEASE-p8 and just started using Apache   
2.0.50 with PHP 4.3.7-3.  I immediately ran into a strange problem I've 
never seen before, where when I send mail in IMP (a webmail system I run 
on this server) the child Apache process crashes with the following 
error:

Fatal error 'Unable to read from thread kernel pipe' at line 1100 in file
/usr/src/lib/libc_r/uthread/uthread_kern.c (errno = 0)
[Wed Jul 14 22:29:41 2004] [notice] child pid 3686 exit signal Abort trap 
(6)

Anyone have any ideas as to what's causing this?  I found that error 
message in discussions about gnucash and xscreensaver-demo, but with no 
answers.  I'm not sure whether the problem lies in Apache or somewhere 
else, but because I'm experiencing it in Apache I'm reporting it here on 
the ports list.  Thanks!

W