Oracle Database Discussions

This is I'm sure my stupidity here BUT,

During install and setup of a 10.2.0.1. database, the SYS,SYSTEM & SYSMAN users were assigned the same password. I've had no problems but after reading up on simple security measures for your DB I decided to change passwords for the three. I logged into EM as SYS as SYSDBA and went to USERS. I then changed the SYS password using EM which told me I was successful. I then changed the password for SYSTEM and SYSMAN as well both of which times EM advised that the change was successfull.

Well, it didn't go as advertised because now when I try and log in as any of the three users I get a password error. I'm most definitely using the correct password as they were changed to through EM but I"m still unable to log into the database. Now I've locked the SYSTEM account since I've tried too many times. So, now I'm here asking if I shouldn't have used EM to change passwords or if that shouldn't be done after using the same for all three during install.

Mostly I just have to figure a way to get back into the database as the SYSDBA so I can do some maintenance. I also don't want to operate the thing without being able to administer.

Is this permanently screwed up? Also, any reason why changing the password went wrong?

TIA