11gr2 silent install error - Unable to create a new central inventory direc

Question

I am working on SLES 11 SP2 on zLinux and I am trying to install oracle 11gr2 silently. I was able to install the GI and it is running but when I try to install the oracle binaries I keep getting this error:
[FATAL] [INS-32035] Unable to create a new central inventory directory : /opt/oraInventory.
CAUSE: The central inventory location provided is not empty.
The GI install created /opt/oraInventory and all the files are in there. I even changed the owner from grid:oinstall to oracle:oinstall but that did not help. When I did the install on SLES 11 SP1 I did not get this error.
I am running this command to install oracle: /runInstaller -silent -ignorePrereq -showProgress -waitForCompletion -responseFile /tmp/db_install.rsp
drwxrwx--- 6 oracle oinstall 4096 Apr 2 10:42 oraInventory
drwxrwx--- 2 oracle oinstall 4096 Apr 2 10:39 ContentsXML
drwxrwx--- 3 oracle oinstall 4096 Apr 2 10:41 backup
drwxrwx--- 2 oracle oinstall 4096 Apr 2 10:41 logs
-rw-rw-r-- 1 oracle oinstall 52 Apr 2 10:41 oraInst.loc
-rwxrwx--- 1 oracle oinstall 1650 Apr 2 10:41 orainstRoot.sh
drwxrwx--- 2 oracle oinstall 4096 Apr 2 10:38 oui
cat oraInst.loc
inventory_loc=/opt/oraInventory
inst_group=oinstall

Answer 1

That was my last resort because the support is horrible. I am getting the same error during the GUI install also if that makes a difference. Its like the oracle install does not know about the Grid installed already in oraInventory.