One reason this might be happening is due to the spelling of the email address, sometimes the email might have been mis-typed at the registration stage and then you put the correct spelling when trying to log in and it will say that your email is not recognised.  If you are not receiving any entry confirmation emails from Horse Monkey or pending entry reminders this might be that your registered email is wrong.

Please contact the Horse Monkey team if this is the case so we can help you.