can not start kdesktop_lock

[LeVA <leva@az.isten.hu>]

Hi!

I have kde 3.5.5 (testing). I'm experiencing a weird problem. When 
clicking on the Desktop Lock button on the Lock/Logout applet, or 
pressing the hotkey associated with "Lock Session", then sometimes 
kdesktop_lock won't start. I need to press the button three or four 
times to get it started. I have no error entry in my ~/.xsession-errors 
and have no idea how to debug this :\

I've tried to replace the kdesktop_lock binary with a script which calls 
strace with kdesktop_lock, but it says:
strace: ptrace(PTRACE_TRACEME, ...): Operation not permitted

Any ideas would be appreciated.

Thanks!

ps.: please cc me

Daniel
-- 
LeVA