I did a fresh install on X 2.2.1 everything works ace, except people can't register. I have it set on activate automatically and Allow new user registration is set to YES. The only way that users can log into the site after i had to create a user manually is if i make them a moderator.

This is not a browser or firewall issue as far as i can tell.

No one can register to my site, it just redirects when you try to register.

I create a user, try to log in and it does the same thing, redirects and you cant log in.

The only way for people to log into my site is if i create a user and give them moderator status..

I'm having the same issue - 'Register Now!' just redirects from register.php to user.php?xoops_redirect=%2Fmodules%2Fprofile%2Fregister.php&
It's the lost password page.
I've tried it in both Firefox and Avant - both behave exactly the same. Have been trawling the forums looking for a solution without luck.
Only upside is that there seems to be a bunch of hacked sites that didn't upgrade but I'd like to get services back to normal.

Don't forget to install the Extended Profiles module. That is where the registration form is in now.

Yeah I just figured that one out - also, don't forget to make sure you have permissions set so that annonomous users can access the extended profiles module.
That did it for me.