I've tried to use a manuall upgrade to php 5.4 using Debian squeeze. After not achieving what I wanted I moved back to php 5.3. Now the webserver does not seem to honor the linux user and group - if a webuser (the linux user) tries to write into a cache folder (within a webfolder) I get a "not writable" exception. Setting the cache folder to 777 (just for testing purposes) worked. How can I reconfigure apache / php to (re)honor ispconfigs security policy on web-folder owners? Any help is welcome. Edit: If I change the owner of the cache folder to www-data it works fine.