OpenVPN:/sys/devices/virtual/net/tap0: couldn't determine device driver; ignoring...

[tbys]

As requested, I have reproduced bug #1071138 in 12.04.

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: network-manager 0.9.4.0-0ubuntu4.1
ProcVersionSignature: Ubuntu 3.2.0-32.51-generic 3.2.30
Uname: Linux 3.2.0-32-generic x86_64
NonfreeKernelModules: nvidia
ApportVersion: 2.0.1-0ubuntu13
Architecture: amd64
CRDA: Error: command ['iw', 'reg', 'get'] failed with exit code 1: nl80211 not found.
Date: Fri Oct 26 21:56:22 2012
IfupdownConfig:
 auto lo
 iface lo inet loopback
InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Release amd64 (20120425)
IpRoute:
 default via 10.11.12.1 dev eth0 proto static
 10.11.12.0/24 dev eth0 proto kernel scope link src 10.11.12.3 metric 1
 xxx.xxx.xxx.xxx/16 dev eth0 scope link metric 1000
IwConfig:
 lo no wireless extensions.

 eth0 no wireless extensions.
NetworkManager.state:
 [main]
 NetworkingEnabled=true
 WirelessEnabled=true
 WWANEnabled=true
 WimaxEnabled=true
RfKill:

SourcePackage: network-manager
UpgradeStatus: No upgrade log present (probably fresh install)
nmcli-con:
 NAME UUID TYPE TIMESTAMP TIMESTAMP-REAL AUTOCONNECT READONLY DBUS-PATH
 xxxx.xxxx.xxxx (openvpn) 923c15e0-67d6-4fd2-acc1-82934873c288 vpn 0 never yes no /org/freedesktop/NetworkManager/Settings/1
 Wired connection 1 68144dee-7333-415c-b09e-3ca6318669b6 802-3-ethernet 1351256032 2012年10月26日 21時53分52秒 yes no /org/freedesktop/NetworkManager/Settings/0
nmcli-dev:
 DEVICE TYPE STATE DBUS-PATH
 eth0 802-3-ethernet connected /org/freedesktop/NetworkManager/Devices/0
nmcli-nm:
 RUNNING VERSION STATE NET-ENABLED WIFI-HARDWARE WIFI WWAN-HARDWARE WWAN
 running 0.9.4.0 connected enabled enabled enabled enabled disabled