Newly installed FreeBSD but Gnome problem

I have newly installed FreeBSD 11 with gnome as per FreeBSD book everything i did what is in docs but when I start pc, gnome starts but various things not working like USB auto detect and log out button in gnome and gnome gets automatically logout me as user and gives login screen etc many problems. Sometimes after rebooting everything works fine but most of the time these things don't work. Strange. Looks problem in gnome or anything like that.
I have added already after installatiion of FREEBSD all the four lines dbus hald gdm and gnome lines but problem is there.