Error: "ORA-01017: Invalid username/password; logon denied" when trying to connect to 11g database. (4309628)

PROBLEM 1:

When trying to connect to an 11g database from the command line or within Toad, the following error, "ORA-01017: Invalid username/password; logon denied" is received.  Connection to a 10g database through the command line works, but not to 11g.  Connecting via SQL Plus also works fine.

PROBLEM 2:

After password expired and changing the password (and verifying change), receive ORA-01017: Invalid username/password; logon denied.

CAUSE 1:

Case sensitive passwords were introduced in Oracle 11g. When connecting to a database using Toad versions 9.1 and below the password is sent all UPPERCASE. Hence, the ORA-01017 error if the users password contains lowercase characters. Toad versions 9.1 and below do not support 11g Oracle Database.

CAUSE 2:

If connected to an 11g database using an Oracle 10g client then the password change fails. This also fails in SQL*PLUS. This is an Oracle issue.

RESOLUTION 1:

Upgrade to Toad for Oracle 9.5 or higher.

RESOLUTION 2:

Upgrade the Oracle Client to an 11g client.