I have a 871W with IOS 12.4(4)T7 and every few hours the wireless interface goes down, all of the computers connect to the interface show the connection is still alive yet no traffic is sent or received. The wired computer continue to function properly. To fix the problem the router needs to be rebooted and everything is fine for several hours until the next crash. I have tried changing channels and disabling advanced security settings (thinking that mal formed http headers were causing the interface to shutdown ). At this point I am at a complete loss. Has anyone else had these issues?