When trying to connect to a database with a password that contains a parenthesis ( ; ) in it, the following error appears:
'ERROR  [IBM] SQL30082N Security processing failed with reason "24" ("USERNAME AND/OR PASSWORD INVALID"). SQLSTATE=08001'
It is possible to connect to the database with the db2 client but with the Toad for DB2 GUI, the error appears.
Remove the ';' from the password.
Waiting for fix in a future release of Toad For DB2.