Error ORA-01031/ORA-00604 on communication with standby

When I have hit the ORA-01031 error on version 10g, the cause was usually boring - badly configured connection primary<->standby, lack of password file, improper permissions on such file, etc. With 11g version the trivial error become more enigmatic. I checked connections, copied the password file from the primary and still got ORA-01031 on connection from the primary to the standby (and ORA-00604 on the connection from the standby to the primary). Finally under the link https://forums.oracle.com/forums/thread.jspa?messageID=10350931 I have found quite good explanation to my problem.
With the advent of 11g version DEFAULT profile has got some limitations - among others expired passwords. Due to this passwords go through grace time period, when "normal" user sees a message about grace time period. But automatically controlled connection to/from a standby gets lost with this behavior, while returned errors do not indicate the right solution, which is simple of course. One may

• change a password (to solve temporarily)
• or change the DEFAULT profile
• or change SYS profile to less restrictive

One must remember that after any of those operations the current logfile needs to be applied on a standby in order to see a positive change. After that automatic redo shipping started to work properly.

UPDATE on 2013-06-20
It seems that despite possible problems with passwords (which may arise with similar symptoms) in my particular case the true reason behind the ORA-1031/ORA-604 errors is the local coniguration - on the database is enabled VPD technology and an ON LOGON trigger to enforce the required context settings. The connections are successful only if done from a primary to a mounted standby. More on the subject in another article.