[imp] segmentation faults after upgrade to PHP 4.3.2, httpd 2.0.46

[Peter Woit]

After upgrading our horde/imp installation to PHP 4.3.2, httpd 2.0.46,
I can login to imp, but get an INBOX screen that is normal looking (knows
how many messages I have), but with no actual message list. At the
same time, an httpd child segfaults.

Apache/2.0.46 (Unix) mod_ssl/2.0.46 OpenSSL/0.9.7b PHP/4.3.2

[notice] child pid 24036 exit signal Segmentation fault (11)

Comparing the access logs with what used to happen, the following doesn't
show up when things fail

"GET /horde/imp/mailbox.php?mailbox=INBOX&actionID=105 HTTP/1.1" 200 39072

The new PHP was configured as follows:

./configure  --with-imap=/usr/local/src/imap-2002c1-nossl
--with-mysql=/usr/local/mysql --with-gettext --with-zlib
--with-apxs2=/usr/local/apache2/bin/apxs

mysql is version 4.0.13
imap-2002c1 compiled without SSL support

PEAR is installed as follows
Installed packages:
===================
Package        Version State
Archive_Tar    1.1     stable
Console_Getopt 1.0     stable
DB             1.4.0   stable
HTML_Common    1.2     stable
HTTP           1.2     stable
Log            1.6.3   stable
Mail           1.0.1   stable
Mail_Mime      1.2.1   stable
Net_SMTP       1.2.3   stable
Net_Socket     1.0.1   stable
PEAR           1.1     stable
XML_Parser     1.0.1   stable
XML_RPC        1.0.4   stable

All tests (test.php, phpinfo, IMP IMAP test) look fine