pptpd problem

[Mario Lobo]

Hi;

I have a VPN server on FBSD 8.1. The vpn closes fine. But as soon as I start 
doing something with an inside LAN machine i.e. an RDP session, I get this:

May 14 12:46:06 suporte pptpd[1958]: GRE: xmit failed from decaps_hdlc: No 
buffer space available

and the VPN tunnel drops.

I googled a lot for it but I didn't find any thing that could help.
The system WAS working OK before. I tried everything I could think of.

Could anyone help?
Thanks,

-- 
Mario Lobo
http://www.mallavoodoo.com.br
FreeBSD since 2.2.8 [not Pro-Audio.... YET!!] (99% winblows FREE)


pptpd: 
poptop-1.3.4_2

System:
FreeBSD 8.1-STABLE #0: Mon Feb 28 20:47:00 BRT 2011 i386
last pid:  2145;  load averages:  0.00,  0.00,  0.00                                                                                                    
28 processes:  1 running, 27 sleeping
CPU:  0.0% user,  0.0% nice,  0.0% system,  1.1% interrupt, 98.9% idle
Mem: 15M Active, 13M Inact, 58M Wired, 28K Cache, 44M Buf, 1892M Free
Swap: 4000M Total, 4000M Free

sysctl.conf:
security.bsd.see_other_uids=0
security.bsd.see_other_gids=0
debug.cpufreq.lowest=400
kern.maxfiles=65536
kern.maxfilesperproc=32768
kern.maxvnodes=600000
kern.ipc.shmmax=67108864
kern.ipc.shmall=16384
kern.ipc.nmbclusters=32768
kern.ipc.somaxconn=32768
net.inet.tcp.rfc1323=1
net.inet.tcp.drop_synfin=1
net.inet.tcp.sendspace=65536
net.inet.tcp.recvspace=65536
net.inet.tcp.blackhole=2
net.inet.udp.blackhole=1
net.inet.icmp.drop_redirect=1
net.inet.icmp.icmplim_output=0
net.inet.icmp.icmplim=2000
net.inet.tcp.path_mtu_discovery=0
net.inet.tcp.recvbuf_auto=1
net.inet.tcp.recvbuf_inc=16384
net.inet.tcp.recvbuf_max=16777216
net.inet.tcp.sendbuf_auto=1
net.inet.tcp.sendbuf_inc=8192
net.inet.tcp.sendbuf_max=16777216

pf.conf(relevant rules):
#--- Allow vpns from anywhere to anywhere
pass log   quick on $ext_if inet proto gre all queue (ssh_bulk, ack)
pass log   quick on $ext_if inet proto tcp  from any to any port pptp flags 
S/SA queue (ssh_bulk, ack)
  
pass log   quick on $aln_if inet proto gre all queue (ssh_bulk, ack)
pass log   quick on $aln_if inet proto tcp  from any to any port pptp flags 
S/SA queue (ssh_bulk, ack)


options.pptpd:
proxyarp
lock
name 

ppp.conf:
default:
  set timeout 1200
  # set log Phase Chat LCP IPCP CCP TUN Command Connect
  set log Phase Chat TUN Connect
  set dial
  set login
  set ifaddr 172.16.3.200/24 172.16.3.201-172.16.3.239 255.255.255.0
  set server /tmp/tun%d "" 0177
  # set lqrperiod 20
  # set echoperiod 20
  # enable lqr echo

pptp:
  disable ipv6cp pap chap
  disable deflate pred1
  deny deflate pred1
  enable proxy
  accept dns
  set mtu max 1024
  set dns 172.16.3.133
  set nbns 172.16.3.133
  enable MSChapV2
  enable mppe
  set mppe * stateful
  set radius /etc/ppp/radius.conf
  set rad_alive 60
  allow mode direct