Binary package hint: network-manager-gnome
When attempting to connect to a vpnc network from network-manager, the network-manager applet dies. It will not start again until network-manager daemon and vpnc are killed off. Here's the output from daemon.log, the only real interesting output I found.
Apr 17 11:20:30 cobol NetworkManager: <information>^IWill activate VPN connection 'PumpVPN', service 'org.freedesktop.Network
Manager.vpnc', user_name 'ryan', vpn_data 'IPSec gateway / 204.8.82.210 / IPSec ID / PumpVPN', route ''.
Apr 17 11:20:30 cobol NetworkManager: <information>^IVPN Activation (PumpVPN) Stage 1 of 4 (Connection Prepare) scheduled...
Apr 17 11:20:31 cobol NetworkManager: <information>^IVPN Activation (PumpVPN) Stage 1 of 4 (Connection Prepare) ran VPN servi
ce daemon org.freedesktop.NetworkManager.vpnc (PID 8970)
Apr 17 11:20:31 cobol NetworkManager: <information>^IVPN Activation (PumpVPN) Stage 1 of 4 (Connection Prepare) complete.
Apr 17 11:20:31 cobol NetworkManager: <information>^IVPN Activation (PumpVPN) Stage 2 of 4 (Connection Prepare Wait) schedule
d...
Apr 17 11:20:31 cobol NetworkManager: <information>^IVPN service 'org.freedesktop.NetworkManager.vpnc' signaled state change
1 -> 6.
Apr 17 11:20:31 cobol NetworkManager: <information>^IVPN Activation (PumpVPN) Stage 2 of 4 (Connection Prepare Wait) waiting.
..
Apr 17 11:20:31 cobol NetworkManager: <information>^IVPN Activation (PumpVPN) Stage 2 of 4 (Connection Prepare Wait) complete
.
Apr 17 11:20:31 cobol NetworkManager: <information>^IVPN Activation (PumpVPN) Stage 3 of 4 (Connect) scheduled...
Apr 17 11:20:31 cobol NetworkManager: <information>^IVPN Activation (PumpVPN) Stage 3 of 4 (Connect) sending connect request.
Apr 17 11:20:31 cobol NetworkManager: <information>^IVPN Activation (PumpVPN) Stage 3 of 4 (Connect) request sent, waiting fo
r reply...
Apr 17 11:20:31 cobol NetworkManager: <information>^IVPN service 'org.freedesktop.NetworkManager.vpnc' signaled state change
6 -> 3.
Apr 17 11:20:31 cobol NetworkManager: <information>^IVPN service 'org.freedesktop.NetworkManager.vpnc' signaled state change
3 -> 6.
Apr 17 11:20:31 cobol NetworkManager: <WARNING>^I nm_vpn_service_stop_connection (): (VPN Service org.freedesktop.NetworkMana
ger.vpnc): could not stop connection 'PumpVPN' because service was 6.
Apr 17 11:20:31 cobol NetworkManager: file nm-vpn-service.c: line 459 (nm_vpn_service_stage3_connect_cb): assertion failed: (
service != NULL)
If this still does not work, do you fill in both group name and password? There is a bug that couses NM to crash when only one field of these is used.