Strange Session Behavior

Hey there, One of the guys I work with has build a neat survey app. It uses sessions to track the user through the steps of creating the survey. Anyway, we've been attempting to move it from our dev box to our staging box. There are some minor differences in terms of what is installed on the machines, but nothing seemingly all that significant. It works fine on the dev box (sess_* files are created in /tmp with appropriate data in them). However, when run on staging dev box, the /tmp/sess_* files are created, but they are all 0 bytes (and stay that way). Even the simplest of examples isn't working: <?php session_start(); session_register("count"); $count++; ?> Ideas? The staging server is running Apache 1.3.9 w/ php 4.0.1pl2, and ServletExec on Linux. PHP is compiled as a DSO with xml and mysql. Apache modules loaded are: mod_php4, mod_servletexec, mod_setenvif, mod_so, mod_usertrack, mod_headers, mod_auth, mod_access, mod_alias, mod_cgi, mod_dir, mod_status, mod_mime, mod_log_config, mod_env, mod_vhost_alias, http_core Thanks! seth