Here's the configuration for the installation that was failing:
PHP: 5.4.21
MySQL: 5.1.72
Server OS: Linux 2.6.28.8-20120713a-iscsi-ntacker-3ware-sec8-fmon-igb-dif2-grsec
HTTP Server: Apache
Provider: 1and1
Code:
session
Session Support enabled
Registered save handlers files user sqlite
Registered serializer handlers php php_binary wddx
Directive Local Value Master Value
session.auto_start Off Off
session.cache_expire 180 180
session.cache_limiter nocache nocache
session.cookie_domain .mystore.com no value
session.cookie_httponly On Off
session.cookie_lifetime 0 0
session.cookie_path /myadmin /
session.cookie_secure Off Off
session.entropy_file /dev/urandom /dev/urandom
session.entropy_length 32 32
session.gc_divisor 2 100
session.gc_maxlifetime 900 1440
session.gc_probability 1 1
session.hash_bits_per_character 4 4
session.hash_function 0 0
session.name zenAdminID PHPSESSID
session.referer_check no value no value
session.save_handler user files
session.save_path /mystore/cache /tmp
session.serialize_handler php php
session.upload_progress.cleanup On On
session.upload_progress.enabled On On
session.upload_progress.freq 1% 1%
session.upload_progress.min_freq 1 1
session.upload_progress.name PHP_SESSION_UPLOAD_PROGRESS PHP_SESSION_UPLOAD_PROGRESS
session.upload_progress.prefix upload_progress_ upload_progress_
session.use_cookies On On
session.use_only_cookies On On
session.use_trans_sid 0 0
Code:
Session Directory /mystore/cache
Cookie Domain True
Force Cookie Use False
Check SSL Session ID False
Check User Agent False
Check IP Address False
Prevent Spider Sessions True
Recreate Session True
IP to Host Conversion Status true
Use root path for cookie path False
Add period prefix to cookie domain True
Bookmarks