1. Open ports 6112 to 6200 on your router and point them to the PC IP address you're playing on. This isn't generally necessary but it can help.
Done
2. Make sure you don't have some firewall blocking out Demigod. Some router firewalls prevent UDP traffic from getting through.
Done
3. Have you tried the parameter /serverproxyonly in the Demigod shortcut as a parameter? This will have us host your connection for you.
Yes
4. Make sure you don't have a firewall or packet blocker on your own machine as they are designed to block p2p connections.
Now, if you are still having problems, let's walk through what we need:
Don't
#1 Who is your Internet Service Provider (ISP)?
Rogers Cable
#2 What brand and make of router are you using?
D-Link DIR-655
#3 What kind of connection do you have? Cable Modem? DSL? ISDN? ADSL? VDSL? Something else?
Cable
#4 Post your impulsereactor.log file in your comment. It's in your my documents\my games\gas powered games\demigod directory.
http://pastebin.com/f75d82a4d
I've tried a couple more times and there is always the common line near the end of the log when it fails:
[07-17-2009 11:46:04 646] Ready to try and connect.
[07-17-2009 11:46:04 646] CVPOnPlayerDataUpdatedCallback
You are not authorized to make this request
#5 Describe clearly and specifically what problem you are having. What were you trying to do? What did you see on the screen? What did the connectivity dialog say? The more information we have, the better we can help you.
I have no problems finding games and connecting. Pings look fine in lobby. Once I connect my pings spike into the thousands. Everyone yells at me. It makes me feel bad.
I have great connections with other multiplayer games. Just tested with team fortress 2 32 player match and my ping stayed below 50.
I have had the odd successful match, but recently no luck at all.
After trying a few matches after opening ports etc. people are now saying to kick me and won't let me in any games. Hopefully once you figure out what's wrong I can direct them to this thread to exonerate myself 
BTW, I am a computer engineer with networking experience, and recently sent in my resume, If you need some extra help with this look me up 