ORA-01033: ORACLE initialization or shutdown in progress
Our work around by the way is comment in client tnsnames files the address line of de standby, but this not the data guard idea.
Our database is 11gR2 version (11.2.0.3)
Operating System Solaris 10
Oracle client versions, 10.1, 11.1 and 11.2
Our clients are .Net application using web services.