If you see a white blank page after registering:
It means your email or IP address is in some blacklists and no account has been created.
That may happen if you are on a VPN, or on a shared public IP, or your home IP has been previously assigned to a spammer, or other weird reasons (it happened to an user who registered in another forum many months before and his email went in a blacklist).
Unfortunately it's not possible to disable this useful and necessary feature without (immediate) negative results.
If the captcha says to retry:
Don't worry, retry again till it will work. It's just a simple annoyance happening during registration so relax
Obviously feedback is welcome but... if you can comment here it means you don't have such problems
