Error with Thread

Hello, i'm using version 1.1.8, my OS is Linux (Gentoo). My server stop and log this: Error: FATAL: Thread create failed: Resource temporarily unavailable Before this log, have: Wed Jun 29 00:16:13 2011 : Error: Dropping conflicting packet from client client1:41250 - ID: 195 due to unfinished request 155365 Wed Jun 29 00:16:13 2011 : Error: Dropping conflicting packet from client client2:59253 - ID: 235 due to unfinished request 155374 My config for start server is: start_servers = 200 max_servers = 200 min_spare_servers = 10 max_spare_servers = 200 max_requests_per_server = 0 The server only returns if I restart the service Thanks Jean