Redmine

I have a redmine version :

• Redmine : 0.8.0.stable.2205
• Ruby : ruby 1.8.6 (2008-08-11 patchlevel 287) [i686-linux]
• Rails : Rails-2.1.2
• Postgresql : (PostgreSQL) 8.2.7
• SCM : git version 1.6.0.6
• Deploy : Thin+Nginx (1 thin server)

Sometimes after a undefined time, my redmine process get 100% of CPU and memory grow up indefinitely. A munin graph show that : http://shingara.fr/export/munin/shinydedi/shinydedi/index.html