You have to re-register if you clear your browser details, which I do, as a matter of course, after finishing Internet banking or other personal matters online.
I would rather re-register than risk a hacker getting hold of private information about me or my bank accounts!
However, it would have nice if Gransnet's moderators warned one of this fact.
What drives me mad, is that on Gransnet when you enter your e-mail and then want to enter your password, you cannot just use Enter. If you try, you are told that your details are wrong.
No other site I have yet found on the Internet has this particular quirk, so I am often caught out, as my right hand little finger automatically uses enter to change lines.