thanks for your help!
Zend optimizer is not installed, true
and RG is an optional, not nessesary for script to run properly, it just enables the function of image uploads for users.
What i care about is Output Buffering, that must be turned off.
I logged to zend.com to dl the version of Zend Optimizer, but i'm not sure what version to install ? It seems that they don't have Debian v.
All they have is
Darwin 8.6 Universal
FreeBSD x86 5.x
FreeBSD x86 6.x
Solaris Sparc x64
Solaris Sparc 8,9,10
Solaris x86 9,10
And is there any instructions on how to install zend optimizer for dummies ? I haven't find anything in DH wiki/