LinuxQuestions.org - issues with VPN pptpd server

Hello everybody!
I'm getting annoying error while connecting to my pptpd server:
================================
Aug 25 10:33:19 social pptpd[3227]: CTRL: Made a START CTRL CONN RPLY
packet
Aug 25 10:33:19 social pptpd[3227]: CTRL: I wrote 156 bytes to the
client.
Aug 25 10:33:19 social pptpd[3227]: CTRL: Sent packet to client
Aug 25 10:33:20 social pptpd[3227]: CTRL: Received PPTP Control Message
(type: 7)
Aug 25 10:33:20 social pptpd[3227]: CTRL: Set parameters to 10000000
maxbps, 3 window size
Aug 25 10:33:20 social pptpd[3227]: CTRL: Made a OUT CALL RPLY packet
Aug 25 10:33:20 social pptpd[3227]: CTRL: Starting call (launching pppd,
opening GRE)
Aug 25 10:33:20 social pptpd[3227]: CTRL: pty_fd = 4
Aug 25 10:33:20 social pptpd[3227]: CTRL: tty_fd = 5
Aug 25 10:33:20 social pptpd[3228]: CTRL (PPPD Launcher): program binary
= /usr/sbin/pppd
Aug 25 10:33:20 social pptpd[3228]: CTRL (PPPD Launcher): local address
= 10.100.8.1
Aug 25 10:33:20 social pptpd[3228]: CTRL (PPPD Launcher): remote address
= 10.100.8.2
Aug 25 10:33:20 social pppd[3228]: Plugin
/usr/lib/pptpd/pptpd-logwtmp.so loaded.
Aug 25 10:33:20 social pppd[3228]: pptpd-logwtmp: $Version$
Aug 25 10:33:20 social pptpd[3227]: CTRL: I wrote 32 bytes to the
client.
Aug 25 10:33:20 social pptpd[3227]: CTRL: Sent packet to client
Aug 25 10:33:20 social pptpd[3227]: GRE: Bad checksum from pppd.
Aug 25 10:33:50 social pptpd[3227]: GRE:
read(fd=4,buffer=804e6c0,len=8196) from PTY failed: status = -1 error =
Input/output error, usually caused by unexpected termination of pppd,
check option syntax and pppd logs
Aug 25 10:33:50 social pptpd[3227]: CTRL: PTY read or GRE write failed
(pty,gre)=(4,5)
Aug 25 10:33:50 social pptpd[3227]: CTRL: Reaping child PPP[3228]
Aug 25 10:33:50 social pptpd[3227]: CTRL: Client 172.16.3.33 control
connection finished
Aug 25 10:33:50 social pptpd[3227]: CTRL: Exiting now
Aug 25 10:33:50 social pptpd[3015]: MGR: Reaped child 3227
Aug 25 10:34:17 social pptpd[2752]: CTRL: Received PPTP Control Message
(type: 5)
Aug 25 10:34:17 social pptpd[2752]: CTRL: Made a ECHO RPLY packet
Aug 25 10:34:17 social pptpd[2752]: CTRL: I wrote 20 bytes to the
client.
Aug 25 10:34:17 social pptpd[2752]: CTRL: Sent packet to client
Aug 25 10:34:19 social pptpd[3261]: MGR: Launching /usr/sbin/pptpctrl to
handle client
Aug 25 10:34:19 social pptpd[3261]: CTRL: local address = 10.100.8.1
Aug 25 10:34:19 social pptpd[3261]: CTRL: remote address = 10.100.8.3
Aug 25 10:34:19 social pptpd[3261]: CTRL: pppd options file =
/etc/ppp/pptpd.options.vpn
Aug 25 10:34:19 social pptpd[3261]: CTRL: Client 172.16.3.33 control
connection started
Aug 25 10:34:19 social pptpd[3261]: CTRL: Received PPTP Control Message
(type: 1)
Aug 25 10:34:19 social pptpd[3261]: CTRL: Made a START CTRL CONN RPLY
packet
Aug 25 10:34:19 social pptpd[3261]: CTRL: I wrote 156 bytes to the
client.
Aug 25 10:34:19 social pptpd[3261]: CTRL: Sent packet to client
Aug 25 10:34:20 social pptpd[3261]: CTRL: Received PPTP Control Message
(type: 7)
Aug 25 10:34:20 social pptpd[3261]: CTRL: Set parameters to 10000000
maxbps, 3 window size
Aug 25 10:34:20 social pptpd[3261]: CTRL: Made a OUT CALL RPLY packet
Aug 25 10:34:20 social pptpd[3261]: CTRL: Starting call (launching pppd,
opening GRE)
Aug 25 10:34:20 social pptpd[3261]: CTRL: pty_fd = 4
Aug 25 10:34:20 social pptpd[3261]: CTRL: tty_fd = 5
Aug 25 10:34:20 social pptpd[3262]: CTRL (PPPD Launcher): program binary
= /usr/sbin/pppd
Aug 25 10:34:20 social pptpd[3262]: CTRL (PPPD Launcher): local address
= 10.100.8.1
Aug 25 10:34:20 social pptpd[3262]: CTRL (PPPD Launcher): remote address
= 10.100.8.3
Aug 25 10:34:20 social pppd[3262]: Plugin
/usr/lib/pptpd/pptpd-logwtmp.so loaded.
Aug 25 10:34:20 social pppd[3262]: pptpd-logwtmp: $Version$
Aug 25 10:34:20 social pptpd[3261]: CTRL: I wrote 32 bytes to the
client.
Aug 25 10:34:20 social pptpd[3261]: CTRL: Sent packet to client
Aug 25 10:34:20 social pptpd[3261]: GRE: Bad checksum from pppd.
Aug 25 10:34:28 social pptpd[3015]: CTRL: Closing child BCrelay with pid
0
Aug 25 10:34:50 social pptpd[3261]: GRE:
read(fd=4,buffer=804e6c0,len=8196) from PTY failed: status = -1 error =
Input/output error, usually caused by unexpected termination of pppd,
check option syntax and pppd logs
Aug 25 10:34:50 social pptpd[3261]: CTRL: PTY read or GRE write failed
(pty,gre)=(4,5)
Aug 25 10:34:50 social pptpd[3261]: CTRL: Reaping child PPP[3262]
Aug 25 10:34:50 social pptpd[3261]: CTRL: Client 172.16.3.33 control
connection finished
Aug 25 10:34:50 social pptpd[3261]: CTRL: Exiting now
=========================================

And the finally, my connection getting lost.

But, when I'm connecting from external network, VPN connection
established pretty fine.

And what is most strage, this configuration worked few days ago, but no luck now.

Does anybody saw such issue?

Useful info:
================================
Poptop v1.2.1

cat /etc/pptpd.conf
====================
option /etc/ppp/pptpd.options.vpn
debug
logwtmp
speed 57600
localip 10.100.8.1
remoteip 10.100.8.2-245

cat /etc/ppp/pptpd.options.vpn
==============================
debug ## change 'servername' to whatever you specify as your server name
in chap-secrets
name test
auth
require-pap
login
ms-dns 10.61.0.4
proxyarp

Debian linux sarge;
uname -a
================================
Linux social 2.6.8-2-686 #1 Tue Aug 16 13:22:48 UTC 2005 i686 GNU/Linux

lsmod | grep ppp

ppp_deflate 6336 2
zlib_deflate 22776 1 ppp_deflate
ppp_async 11648 1
crc_ccitt 2144 1 ppp_async
ppp_generic 30164 7 ppp_deflate,bsd_comp,ppp_async
slhc 7488 1 ppp_generic