VPN service fails after update applied in Debian Squeeze

Hello everybody,

I used to log in to my office via PPTP VPN, but on last October 5th I updated my installed Debian Squeeze and it caused my VPN service (client-side) to fail. After this upgrade I'm unable to log in to the VPN server. Here follows the log:

#tail -f /var/log/messages
Plugin /usr/lib/pppd/2.4.5/nm-pptp-pppd-plugin.so loaded.
pppd 2.4.5 started by root, uid 0
Using interface ppp0
Connect: ppp0 <--> /dev/pts/2
LCP: timeout sending Config-Requests
Connection terminated.
Modem hangup.
Exit.

According to the log I saved I see the following packages were upgraded:

libnm-glib-vpn1
network-manager

as well as some others (including the Linux kernel).

I reset my VPN configuration via Gnome's Network Manager without satisfactory results.

The authentication method I use is CHAPv2.

Could you please give me a hand to solve my VPN connection issue?

---------- Post updated 10-08-12 at 06:53 AM ---------- Previous update was 10-07-12 at 07:09 AM ----------

Here you are some new fresh information that might be useful to debug this issue:

root@thunderbox:/home/thor# tail -f /var/log/messages
[
...
]
Oct 8 08:21:42 thunderbox pppd[3357]: Plugin /usr/lib/pppd/2.4.5/nm-pptp-pppd-plugin.so loaded.
Oct 8 08:21:42 thunderbox kernel: [ 244.066976] PPP generic driver version 2.4.2
Oct 8 08:21:42 thunderbox pppd[3357]: pppd 2.4.5 started by root, uid 0
Oct 8 08:21:42 thunderbox pppd[3357]: Using interface ppp0
Oct 8 08:21:42 thunderbox pppd[3357]: Connect: ppp0 <--> /dev/pts/2
Oct 8 08:21:45 thunderbox pppd[3357]: Connection terminated.
Oct 8 08:21:45 thunderbox pppd[3357]: Exit.

root@thunderbox:/home/thor# tail -f /var/log/debug
[
...
]
Oct 8 08:21:42 thunderbox modem-manager: (net/ppp0): could not get port's parent device

I think it is specially important this part: modem-manager: (net/ppp0): could not get port's parent device. This looks strange for me. However, I'd noticed this message appears when I open Virtual Box, look at this:

Oct 8 08:48:38 thunderbox modem-manager: (net/vboxnet0): could not get port's parent device

I don't want to deviate what I am looking to be solved, but I think the output above might be useful, too.

How to regain access to my VPN? Please suggest.