mail sent.
BUT i think i got it !
Here is how to make it crash so try to recreate it.
Let's say :
1 - i made a user "led" with "ioftpd" default group, this guy uploads a load of shit in \stock where he has permissions.
2 - i realize that this "led" guy has very weird sexual attractions cause he uploads me alot of zooporn ...so i decide to delete his account.
3 - i log into my ioftpd server with default account "ioFTPD" and files that "led" uploaded have now "Nobody" as owner, group still remain the same.
I presume"Nobody" is default owner when ioftpd cant find the user in user files and group is still "ioftpd" cause it still exists : all is OK for me.
4 - I decide to delete his stuff in \stock (subdirs and files) with my "ioftpd" user and here we go, it crashes !
Let me know if you got it or should i like zooporn ?