PPTP VPN connection suddenly playing up

I've got an Intel Mac mini running 10.5.2 Server behind an 802.11n AirPort Extreme. It does VPN/AFP/OD/DNS/DHCP, etc. The whole setup has been working flawlessly, but sometime over the last few days the VPN has pretty much shat itself. There haven't been any software changes whatsoever. I've only got port 1723 forwarded from the Extreme to the mini. Generally what happens when I connect now is either it'll just come up with an error saying "Could not negotiate a connection with the remote server", or it [i]will[/i] connect but there's absolutely no data being transferred through the connection. When that happens I can't even ping the remote IP of the server (10.0.1.253) or anything. When it errors out and doesn't connect at all this is what the logs have: [quote][code]Apr 17 16:38:00 pppd[1001]: pppd 2.4.2 (Apple version 314) started by root, uid 506 Apr 17 16:38:00 pppd[1001]: PPTP connecting to server 'xxxxxxxx' (xxx.xxx.xxx.xxx)... Apr 17 16:38:01 pppd[1001]: PPTP connection established. Apr 17 16:38:01 pppd[1001]: Connect: ppp0 socket[34:17] Apr 17 16:38:31 pppd[1001]: LCP: timeout sending Config-Requests Apr 17 16:38:31 pppd[1001]: Connection terminated. Apr 17 16:38:31 pppd[1001]: PPTP disconnecting... Apr 17 16:38:31 pppd[1001]: PPTP disconnected[/code][/quote] When the connection occurs it gives this: [quote][code]Apr 17 16:41:35 pppd[1010]: pppd 2.4.2 (Apple version 314) started by root, uid 506 Apr 17 16:41:35 pppd[1010]: PPTP connecting to server 'xxxxxxxx' (xxx.xxx.xxx.xxx)... Apr 17 16:41:35 pppd[1010]: PPTP connection established. Apr 17 16:41:35 kernel[0]: pptp_input unexpected, so = 0x38de000, len = 29 Apr 17 16:41:35 pppd[1010]: Connect: ppp0 socket[34:17] Apr 17 16:41:39 pppd[1010]: MPPE 128-bit stateless compression enabled Apr 17 16:41:39 pppd[1010]: local IP address 10.0.1.241 Apr 17 16:41:39 pppd[1010]: remote IP address 10.0.1.253 Apr 17 16:41:39 pppd[1010]: primary DNS address 10.0.1.253 Apr 17 16:41:39 pppd[1010]: secondary DNS address 10.0.1.253 Apr 17 16:41:39 mDNSResponder[23]: Note: DNS Server 10.0.1.253 for domain core. registered more than once[/code][/quote] And now that I'm looking at that I haven't seen the "pptp_input unexpected" message before. After a few minutes the connection will disconnect and give an error "The connection was terminated because the remote side is not responding". I fiddled around a while ago trying to get L2TP to work but never got it going. I can give that another try, and I will grant that I haven't actually tried restarting the server yet (I'm at work right now and seeing as how I can't VPN in I can't remotely restart it!). I [i]have[/i] tried restarting the VPN service last night though, which evidently had no effect. Any thoughts?