Thx for the response Bastien
i removed (require 'org-install) from my init.el file (correct?) and restarted emacs but get the same error
Invalid function: org-babel-header-args-safe-fn
i also tried now to downgrade to previous version from 3/8/15 and the error is gone so its 100% reproducible with the 5/8/15 elpa version
thx again
Z