Phusion-passenger crash

I'm using passenger with apache to run my ruby application. I've noticed that passenger crashes from time to time (apache is still working), and I need to manually restart apache to make it work again.

A look at the log makes me think it occurs when apache changes the log file (archives the current an create a new one). This is what a tail -F on tha apache errors log file looks like:

tail: ‘/var/log/apache2/error.log’ has become inaccessible: No such file or directory                                           
tail: ‘/var/log/apache2/error.log’ has appeared;  following end of new file                                                     
[ 2013-10-06 05:05:27.2678 10498/7f3f0cf82740 agents/Watchdog/Main.cpp:459 ]: Options: { 'analytics_log_user' => 'nobody', 'default_group' => 'nogroup', 'default_python' => 'python', 'default_ruby' => '/usr/bin/ruby1.9.1', 'default_user' => 'nobody', 'log_level' => '0', 'max_instances_per_app' => '0', 'max_pool_size' => '6', 'passenger_root' => '/var/lib/gems/1.9.1/gems/passenger-4.0.14', 'pool_idle_time' => '300', 'temp_dir' => '/tmp', 'union_station_gateway_address' => 'gateway.unionstationapp.com', 'union_station_gateway_port' => '443', 'user_switching' => 'true', 'web_server_pid' => '18659', 'web_server_type' => 'apache', 'web_server_worker_gid' => '1000', 'web_server_worker_uid' => '1001' }                                                                
[Sun Oct 06 05:05:27 2013] [error] *** Passenger could not be initialized because of this error: Unable to start the Phusion Passenger watchdog because it encountered the following error during startup: Tried to reuse existing server instance directory /tmp/passenger.1.0.18659, but it has wrong permissions                                                                             
[Sun Oct 06 05:05:27 2013] [notice] Apache/2.2.22 (Ubuntu) PHP/5.4.9-4ubuntu2.2 Phusion_Passenger/4.0.14 configured -- resuming normal operations

• The message mentions a file in /tmp with wrong permissisons, why are they wrong? what should they be? how to make them right?
• The last message "resuming normal operations" seems wrong too since passenger is down. Is it a bug? What does it mean?
• What should I do to prevent this from happening?