FCPX freeze when starting

Hello, everytime I launch FCPX I get the "Restoring the window layout" step and it freeze. I trash the prefs and then it works, but I cannot live any longer like this. I'm on Lion 10.7.5.
Any thoughts ?

It sounds like a permissions problem. First try repairing permissions with Disk Utility. Also try making a new user.

OK I've done the permission change, I will see if in normal operations it works now, thanks

well, no, it still freeze at opening !
I have try :
- trash the prefs, but it works once, I have to trash every time I want to launch FCPX !
- trash the Layout folder in Application support as indicated by Apple on their support page related to this issue, doesn't work !
- Uninstall FCPX and reinstall, doesn't work
- Change the permissions, doesn't work
- Move all events and projects folder on another volume, relaunch and reimport all events in case of curruption, remove, doesn't work..
This drive me crazy, my setup on my Mac Pro is quiet common, nothing special, and the only way for me to work with FCPX is to trash the prefs every time I want to launch FCPX !

System specs?
Did you fill out the feedback page for Apple?