I've just done a fresh install with network-manager-openvpn on a laptop.
Adding my keys to create  a new connection fails with the Need Secrets message immediately after installation.

I can confirm a succesful connection after a reboot without applying the dbus patch I used on  my other machines. I will post back if it fails for me at some point, but the most consistent element in the behaviour experienced by most of us is that a new nm openvpn configration does not work until after a reboot. 
At this point the gnome  keyring tool opens and asks to give access to the application.
I chose to allow it to remain authorised for future connections.

As I've now seen it work both with and without the dbus patch,
I must conclude that the dbus fix was coincidental with my reboot and of no inherent merit.

(/var/log/daemon.log for the failed connection before reboot)
Nov 12 16:42:43 mynetbook NetworkManager: user_connection_updated_cb: assertion `old_connection != NULL' failed
Nov 12 16:42:58 mynetbook NetworkManager: <info>  Starting VPN service 'org.freedesktop.NetworkManager.openvpn'...
Nov 12 16:42:58 mynetbook NetworkManager: <info>  VPN service 'org.freedesktop.NetworkManager.openvpn' started (org.freedesktop.NetworkManager.openvpn), PID 3539
Nov 12 16:42:58 mynetbook NetworkManager: <info>  VPN service 'org.freedesktop.NetworkManager.openvpn' just appeared, activating connections
Nov 12 16:42:58 mynetbook NetworkManager: nm-vpn-connection.c.828: NeedSecrets failed: dbus-glib-error-quark Rejected send message, 1 matched rules; type="method_call", sender=":1.3" (uid=0 pid=751 comm="NetworkManager) interface="org.freedesktop.NetworkManager.VPN.Plugin" member="NeedSecrets" error name="(unset)" requested_reply=0 destination="org.freedesktop.NetworkManager.openvpn" (uid=0 pid=3539 comm="/usr/lib/network-manager-openvpn/nm-openvpn-servic"))
Nov 12 16:42:58 mynetbook NetworkManager: <WARN>  connection_state_changed(): Rejected send message, 1 matched rules; type="method_call", sender=":1.3" (uid=0 pid=751 comm="NetworkManager) interface="org.freedesktop.NetworkManager.VPN.Plugin" member="Disconnect" error name="(unset)" requested_reply=0 destination="org.freedesktop.NetworkManager.openvpn" (uid=0 pid=3539 comm="/usr/lib/network-manager-openvpn/nm-openvpn-servic"))
Nov 12 16:42:58 mynetbook NetworkManager: <info>  Policy set 'Auto WIFI' (wlan0) as default for routing and DNS.
Nov 12 16:43:11 mynetbook NetworkManager: <debug> [1258044191.000801] ensure_killed(): waiting for vpn service pid 3539 to exit
Nov 12 16:43:11 mynetbook NetworkManager: <debug> [1258044191.001142] ensure_killed(): vpn service pid 3539 cleaned up
=================================================================================

(/var/log/daemon.log output of the succesful connection:)
Nov 12 17:46:52 mynetbook NetworkManager: <info>  Starting VPN service 'org.freedesktop.NetworkManager.openvpn'...
Nov 12 17:46:53 mynetbook NetworkManager: <info>  VPN service 'org.freedesktop.NetworkManager.openvpn' started (org.freedesktop.NetworkManager.openvpn), PID 2325
Nov 12 17:46:53 mynetbook NetworkManager: <info>  VPN service 'org.freedesktop.NetworkManager.openvpn' just appeared, activating connections
Nov 12 17:46:53 mynetbook NetworkManager: <info>  VPN plugin state changed: 3
Nov 12 17:46:53 mynetbook NetworkManager: <info>  VPN connection 'MyOpenVPNconnection' (Connect) reply received.
Nov 12 17:46:53 mynetbook nm-openvpn[2330]: OpenVPN 2.1_rc19 i486-pc-linux-gnu [SSL] [LZO2] [EPOLL] [PKCS11] built on Oct 13 2009
Nov 12 17:46:53 mynetbook nm-openvpn[2330]: NOTE: the current --script-security setting may allow this configuration to call user-defined scripts
Nov 12 17:46:53 mynetbook nm-openvpn[2330]: /usr/bin/openssl-vulnkey -q -b 1024 -m <modulus omitted>
Nov 12 17:46:53 mynetbook nm-openvpn[2330]: LZO compression initialized
Nov 12 17:46:53 mynetbook nm-openvpn[2330]: UDPv4 link local: [undef]
Nov 12 17:46:53 mynetbook nm-openvpn[2330]: UDPv4 link remote: IP.ADD.RESS.XXX:1194
Nov 12 17:46:56 mynetbook nm-openvpn[2330]: WARNING: 'link-mtu' is used inconsistently, local='link-mtu 1542', remote='link-mtu 1442'
Nov 12 17:46:56 mynetbook nm-openvpn[2330]: WARNING: 'tun-mtu' is used inconsistently, local='tun-mtu 1500', remote='tun-mtu 1400'
Nov 12 17:46:56 mynetbook nm-openvpn[2330]: [HOSTNAME.TLD] Peer Connection Initiated with IP.ADD.RESS.XXX:1194
Nov 12 17:46:57 mynetbook nm-openvpn[2330]: TUN/TAP device tun0 opened
Nov 12 17:46:57 mynetbook nm-openvpn[2330]: /sbin/ifconfig tun0 192.168.5.6 pointopoint 192.168.5.5 mtu 1500
Nov 12 17:46:57 mynetbook NetworkManager:    SCPlugin-Ifupdown: devices added (path: /sys/devices/virtual/net/tun0, iface: tun0)
Nov 12 17:46:57 mynetbook NetworkManager:    SCPlugin-Ifupdown: device added (path: /sys/devices/virtual/net/tun0, iface: tun0): no ifupdown configuration found.
Nov 12 17:46:57 mynetbook nm-openvpn[2330]: /usr/lib/network-manager-openvpn/nm-openvpn-service-openvpn-helper tun0 1500 1542 192.168.5.6 192.168.5.5 init
Nov 12 17:46:57 mynetbook NetworkManager: <info>  VPN connection 'MyOpenVPNconnection' (IP Config Get) reply received.
Nov 12 17:46:57 mynetbook NetworkManager: <info>  VPN Gateway: IP.ADD.RESS.XXX
Nov 12 17:46:57 mynetbook NetworkManager: <info>  Internal Gateway: 192.168.5.5
Nov 12 17:46:57 mynetbook NetworkManager: <info>  Tunnel Device: tun0
Nov 12 17:46:57 mynetbook NetworkManager: <info>  Internal IP4 Address: 192.168.5.6
Nov 12 17:46:57 mynetbook NetworkManager: <info>  Internal IP4 Prefix: 32
Nov 12 17:46:57 mynetbook NetworkManager: <info>  Internal IP4 Point-to-Point Address: 192.168.5.5
Nov 12 17:46:57 mynetbook NetworkManager: <info>  Maximum Segment Size (MSS): 0
Nov 12 17:46:57 mynetbook NetworkManager: <info>  Static Route: 192.168.0.0/24   Next Hop: 192.168.0.0
Nov 12 17:46:57 mynetbook NetworkManager: <info>  Static Route: 192.168.5.0/24   Next Hop: 192.168.5.0
Nov 12 17:46:57 mynetbook NetworkManager: <info>  Internal IP4 DNS: 192.168.0.4
Nov 12 17:46:57 mynetbook nm-openvpn[2330]: Initialization Sequence Completed
Nov 12 17:46:57 mynetbook NetworkManager: <info>  DNS Domain: 'MyOpenVPN.tld'
Nov 12 17:46:57 mynetbook NetworkManager: <info>  Login Banner:
Nov 12 17:46:57 mynetbook NetworkManager: <info>  -----------------------------------------
Nov 12 17:46:57 mynetbook NetworkManager: <info>  (null)
Nov 12 17:46:57 mynetbook NetworkManager: <info>  -----------------------------------------
Nov 12 17:46:58 mynetbook NetworkManager: <info>  VPN connection 'MyOpenVPNconnection' (IP Config Get) complete.
Nov 12 17:46:58 mynetbook NetworkManager: <info>  Policy set 'Auto WIFI' (wlan0) as default for routing and DNS.
Nov 12 17:46:58 mynetbook NetworkManager: <info>  VPN plugin state changed: 4
Nov 12 17:46:58 mynetbook nm-dispatcher.action: Script '/etc/NetworkManager/dispatcher.d/01ifupdown' exited with error status 1.