Cleaning-up stale PID files on reboot

[RW]

I start mlnet, the daemon part of mldonkey, from it's local rc.d script on 
bootup. If mlnet isn't shutdown properly, it leaves behind a pid file that 
prevents the daemon  running until I notice and manually delete the file. 

What's the best way to deal with this? I was wondering if there is some 
standard place to clean-up after an improper shutdown. 

Is mlnet doing something wrong?  I don't get the same problem with other 
daemons.