Well it seems the problem is that even though the user is dropped and recreated some things stay in the background until they're cleaned up by Oracle.
See for more on this:
http://www.dbaclick.com/forums/archive/20/1422.html
(Ciaran DeBuitlear found this solution)
I had to wait for an hour after dropping user, and then the install continued without above error (still failed though for other reasons) ie.
*** Initializing content repository hierarchy...
declare
*
ERROR at line 1:
ORA-02291: integrity constraint (ENKE_KM.ACS_OBJECTS_CONTEXT_ID_FK) violated -
parent key not found
ORA-06512: at "ENKE_KM.ACS_OBJECT", line 68
ORA-06512: at "ENKE_KM.CONTENT_ITEM", line 146
ORA-06512: at "ENKE_KM.CONTENT_FOLDER", line 34
ORA-06512: at line 5
and then it stopped at:
Completing Install sequence by mounting the main site and other core packages.
SQL*Plus: Release 8.1.7.0.0 - Production on Fri May 23 16:30:33 2003
(c) Copyright 2000 Oracle Corporation. All rights reserved.
Connected to:
Oracle9i Enterprise Edition Release 9.0.1.3.0 - Production
With the Partitioning option
JServer Release 9.0.1.3.0 - Production
declare
*
ERROR at line 1:
ORA-01403: no data found
ORA-06512: at "ENKE_KM.ACS", line 90
ORA-06512: at line 9
