Next strange thing, after one hour of stable working on 5 GHz connected devices lose randomly: Windows Phone 8 doesn't see SSID, IPhone 5 see and work correct, notebook with Wi-Fi adapter Intel Corporation PRO/Wireless 3945ABG see SSID but connection drop every 10-15 seconds.
In logs only
"daemon.info hostapd: wlan0: STA 00:1b:77:89:5f:5b WPA: pairwise key handshake completed (RSN)" before disconnect.