Online Vault Mixing Up passwords ?

I pay both my credit cards and my mother's and father's online and use Norton to remember all th apasswords. It has worked fine up until now until tonight and I was locked out of mone account. i suddenly realsied that since updating to the new NIS program Yesterday, it has mixed up the passwords and my father's password is now being applied to my acocunt and vice versa.

What's happening ?