Issue with registration page on site?

Hi,,

is an issue when signing up for an account it might have something to do with the Captcha code? but im unsure can you please confirm ?
is there an alternative that can be used in the same form to fix this?

Domain: http://tinyurl.com/q54cxpp
Support access is ACTIVE until July 26, 2015 3:19 pm

(please dont post any Images / Brand / Domain links etc here please use
http://tinyurl.com/ for links and http://www.tiikoni.com/tis/ to upload temporary images with links ) - this is due to google finding away to link brand name to wpmudev posts which is really annoying and causing multiple issues)

Thanks

Tom