If you have trouble registering then email support @ iforpowell.com and I can force things though.
The system is not that good but I prefer to spend my time working on IpBike than trying to set up an alternative. It is at least good at keeping the spam away.
It is advisable to 'copy' before you try and post as the captcha stuff is a bit to agresive and the back buttone is not working for everyone. You can at least then paste and have another go.