Hi Till,
I install mod_security package for Fedora 14 x86_64 first, then did a "dummy" check-out to get a better error log. Here is the outcome after the attempt:
http://hostwithsupport.com/bronze-hosting/
[Thu Aug 25 08:23:22 2011] [error] [client 70.155.163.2] PHP Warning: require(../language/.php): failed to open stream: No such file or directory in /var/www/clients/client1/web1/web/wp-content/themes/mk4/ajCart/cart.php on line 15, referer:
http://hostwithsupport.com/bronze-hosting/
[Thu Aug 25 08:23:22 2011] [error] [client 70.155.163.2] PHP Fatal error: require(): Failed opening required '../language/.php' (include_path='.:/usr/share/pear:/usr/share/php') in /var/www/clients/client1/web1/web/wp-content/themes/mk4/ajCart/cart.php on line 15, referer:
http://hostwithsupport.com/bronze-hosting/
[Thu Aug 25 08:23:22 2011] [error] [client 70.155.163.2] PHP Warning: Unknown: open(/var/lib/php/session/sess_nf4qqbjgd577hvrn2rqdg03ju0, O_RDWR) failed: Permission denied (13) in Unknown on line 0, referer:
http://hostwithsupport.com/bronze-hosting/
[Thu Aug 25 08:23:22 2011] [error] [client 70.155.163.2] PHP Warning: Unknown: Failed to write session data (files). Please verify that the current setting of session.save_path is correct (/var/lib/php/session) in Unknown on line 0, referer:
http://hostwithsupport.com/bronze-hosting/
[Thu Aug 25 08:23:22 2011] [error] [client 70.155.163.2] ModSecurity: Warning. Operator GE matched 15 at TX

utbound_anomaly_score. [file "/etc/httpd/modsecurity.d/base_rules/modsecurity_crs_60_correlation.conf"] [line "38"] [msg "Outbound Anomaly Score Exceeded (score 15): The application is not available"] [hostname "hostwithsupport.com"] [uri "/wp-content/themes/mk4/ajCart/cart.php"] [unique_id "TlY@un8AAAEAABTVK3IAAAAI"]
[Thu Aug 25 08:23:39 2011] [error] [client 178.203.174.30] PHP Warning: session_start(): open(/var/lib/php/session/sess_7eq8blaus5bfv85f4cqm1o9nn5, O_RDWR) failed: Permission denied (13) in /var/www/clients/client1/web1/web/wp-content/themes/mk4/functions.php on line 10, referer:
http://clicks.thespecialsearch.com/x...ahRsEnoabBj4k=
[Thu Aug 25 08:23:39 2011] [error] [client 178.203.174.30] PHP Warning: Unknown: open(/var/lib/php/session/sess_7eq8blaus5bfv85f4cqm1o9nn5, O_RDWR) failed: Permission denied (13) in Unknown on line 0, referer:
http://clicks.thespecialsearch.com/x...ahRsEnoabBj4k=
[Thu Aug 25 08:23:39 2011] [error] [client 178.203.174.30] PHP Warning: Unknown: Failed to write session data (files). Please verify that the current setting of session.save_path is correct (/var/lib/php/session) in Unknown on line 0, referer:
http://clicks.thespecialsearch.com/x...ahRsEnoabBj4k=
Any instructions on a resolution would be welcome with open arms. The theme designer has no idea!
Thanks in advance