Here, no more crashes after the update, too. I manually installed the package plus required newer dependencies:
Later, I noticed that printing wasn't possible any more, because the CUPS daemon aborts on startup. This is what I found in /var/log/syslog:
Sep 27 12:44:14 meisterin cupsd: Libgcrypt error: reading `/proc/sys/crypto/fips_enabled' failed: Permission denied - abort
Sep 27 12:44:14 meisterin kernel: [ 4532.516155] type=1503 audit(1254048254.089:11): operation="sysctl" requested_mask="r::" denied_mask="r::" fsuid=0 name="/proc/sys/crypto/fips_enabled" pid=7711 profile="/usr/sbin/cupsd"
It seems that the updated libgcrypt required by xserver-org-core doesn't correctly integrate into Jaunty's AppArmor profile for cupsd. After disabling AppArmor enforcement for cupsd, the daemon started up again:
sudo aa-complain /usr/sbin/cupsd
(This setting persists even after reboots.) A better way would be to update the AppArmor profile, but I didn't want to delve into that. The whole mismatch will resolve itself soon anyway, when the system is upgraded to Karmic.