Quite a bit of information has been going around regarding passwords for PSN accounts, if you do not own the same PS3 console that you created your PSN account on then as a safety procedure you are unable to change your PSN ID’s password directly from the PS3 that you are using and you will need to press the “forgot your password” button on the log-in screen only once (pressing it too much will actually lock you out for 24 hours due to strain on the servers).
Once you press the forgot your password button a message will be sent to the email that is used with the PSN account within 24 hours where you can change it from there, sub-accounts have been getting reports of errors when trying to change their passwords and you may have to call Sony customer support for that matter. The reason this is being done is to make sure the person changing the password is the person who actually owns the account and not the hackers who accessed the account’s passwords when the intrusion occurred. Because of the high amount of password requests through email, PSN has recently had reports of temporary service turn-offs for several minutes to focus on getting these requests through, usually these “turn-offs” are not affecting those playing online, but those trying to log in at those periods of time.
For more information regarding PSN passwords, visit the Official PlayStation Knowledge Center regarding PSN password changes.