I previously had successfully set up a VPN connection that allowed my computer (Windows 7 Professional) to connect to a remote server. Last week, we had to reset our Lynksys WRT54GL wireless router, after which the VPN connection doesn't work anymore.
The problem clearly lies with the WRT54GL router: I still can establish a VPN connection with a wired connection that bypasses the router, or on my home WIFI. OTOH, when attempting either wireless or wired via the WRT54GL router, the message "port opened" is followed for a long time by "connecting to [vpn address] using WAN Miniport (PPTP)", next "connecting to [vpn address] using WAN Miniport (SSTP)", and finally "connecting to [vpn address] using WAN Miniport (L2TP)". In the end, an error code 800 is returned.
I'm no sysadmin wizard at all, and can't see what should have changed in the router configuration. Any help much appreciated, it's driving me crazy.