Members area link to be available as login but not compulsor

[sleuth]

Hi Friends, sorry about the english, perhaps some one can help, I would like to allow members area login to be available but not compulsory, at present it appears if you allow webmaster login in admin, it is compulsorily if you don't allow it in admin, the link is not available (it gives a 404 error if you go to the login link) has anyone found a solution to this, you help is appreciated, thank you.