network manager loses wireless internet connection

wifi connection is lost sometimes, but network indicator always shows established network. It restarts by restarting the computer or remove-install wifi adapter physically.
it seems to me that it appear after flashplugin-installer was installed.

ProblemType: Bug
DistroRelease: Ubuntu 13.04
Package: network-manager-gnome 0.9.8.0-1ubuntu2
ProcVersionSignature: Ubuntu 3.8.0-19.29-generic 3.8.8
Uname: Linux 3.8.0-19-generic i686
ApportVersion: 2.9.2-0ubuntu8
Architecture: i386
CRDA: Error: command ['iw', 'reg', 'get'] failed with exit code 1: nl80211 not found.
Date: Mon Apr 29 14:19:54 2013
ExecutablePath: /usr/bin/nm-connection-editor
IfupdownConfig:
 # interfaces(5) file used by ifup(8) and ifdown(8)
 auto lo
 iface lo inet loopback
InstallationDate: Installed on 2013-04-26 (2 days ago)
InstallationMedia: Ubuntu 13.04 "Raring Ringtail" - Release i386 (20130424)
InterestingModules: b44
IpRoute:
 default via 192.168.1.1 dev wlan0 proto static
 169.254.0.0/16 dev wlan0 scope link metric 1000
 192.168.1.0/24 dev wlan0 proto kernel scope link src 192.168.1.39 metric 9
MarkForUpload: True
NetworkManager.state:
 [main]
 NetworkingEnabled=true
 WirelessEnabled=true
 WWANEnabled=true
 WimaxEnabled=true
ProcEnviron:
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=ru_RU.UTF-8
 SHELL=/bin/bash
RfKill:

SourcePackage: network-manager-applet
UpgradeStatus: No upgrade log present (probably fresh install)
nmcli-con:
 NAME UUID TYPE TIMESTAMP TIMESTAMP-REAL AUTOCONNECT READONLY DBUS-PATH
 Проводное соединение 1 35fe59be-c319-4241-96a3-0d11f8884edf 802-3-ethernet 1367218178 Пн. 29 апр. 2013 12:49:38 yes no /org/freedesktop/NetworkManager/Settings/1
 ffuuu d97f9f32-17fb-45f3-b07e-e8d61aa60280 802-11-wireless 1367223577 Пн. 29 апр. 2013 14:19:37 yes no /org/freedesktop/NetworkManager/Settings/0
nmcli-dev:
 DEVICE TYPE STATE DBUS-PATH
 eth0 802-3-ethernet unavailable /org/freedesktop/NetworkManager/Devices/1
 wlan0 802-11-wireless connected /org/freedesktop/NetworkManager/Devices/0
nmcli-nm:
 RUNNING VERSION STATE NET-ENABLED WIFI-HARDWARE WIFI WWAN-HARDWARE WWAN
 running 0.9.8.0 connected enabled enabled enabled enabled disabled