In odoo 8, i have a problem : I define some rules and logic to access project object. It ok. But, when i add a user in project.project, this user doesn't see the project in his list (private navigation, clear client cache, ctrl +shift + R, ctrl + f5, or other command change nothing)

I think ok, i've a problem in my rules, but not ! 
When i restart server (without modification), the user see the new project ... 

It's server cache problem ? People had same problem ? 
Thanks for your response !