Error during AJAX Communication

[alainb]

Hi I just inatalled OTRS 3.1.7 on CentOS release 5.8 (Final)
I used rpm -ivh otrs-3.1.7-01.noarch.rpm

Everything went fine, the problem is when I click on a ticket i t open the page then a few second a popup open and say Error during AJAX Communication

I checked the HTTP log file and it saids : Software caused connection abort at /opt/otrs/Kernel/Output/HTML/Layout.pm line 1640

I tryed to unstall it and delete everything from OTRS and réinstall it a few time, same errors

on the admin part everything run without problem

[alainb]

Update
I updated perl-JSON and restarted http server

I dont have error in the log file anymore , but the ajax error persist

and only if I click on a ticket all the rest work