We are running fine in both our test and production environments. So far, 8.5.0.6 has not had any issues for us. The biggest 'gotchas' were permissions on the Oracle database for the OD_Instance_Owner and then making sure the database and listener were stopped when I installed the application 8.5.0.0 and its fixpack 8.5.0.6.
The installation script will display 'Congratulations' or 'Installed but with errors, see log.' When it displayed 'installed but with errors', it usually did not install the current arsoracle file and then we stopped both the db and listener and uninstalled and reinstalled 8.5.0.0 successfully and of course then fixpacked successfully also.
Oracle also has a link record to a timetable issue.
Make sure that the account you use to install the app has the proper database references in its profile, if you have any references at all; such as HOME / SID / LIBPATH.