Enterprise Manager :: Grid Control Database Instances Always Down

Installed Grid Control 10.2.0.2.0 on Windows Server 2003R2 32-bit. Immediately upgraded to 10.2.0.5.0. Both install and upgrade went fine, Grid Control can see its own database in the list of targets, looks good.

I then installed Oracle 11gR2 11.2.0.1.0 64-bit on Windows Server 2008R2 64-bit and created a new database. I then installed the 10.2.0.5.0 agent manually on the server via OUI. Agent install went fine, secured and started properly.

The problems I'm having is Grid Control can't seem to see the database instance. If I go to "Targets", GC can see the host just fine, shows that its up and can see targets for the listener (Up), the agent at port 3872 (Up), and the database instance (Down). Drilling down to the database instance, it shows that the instance is not up (though it is as I can connect to it from a different machine and run queries against not) and the Agent Connection to Instance is down with the error:
Failed to connect to database instance: (UNKNOWN OCI STATUS 1804) OCIInitialize. Check ORACLE_HOME and NLS settings etc...

Also, pulling up the "Alerts" tab for errors showed the following for Metrics "Access to Important Tables and Views", "DB Data Files Permissions", and "DB Control Files Permission":

Target: SR3
Type: Database Instance
Metric: Access To Important Tables And Views
Collection Timestamp: Jun 11, 2010 11:11:26 AM
Error Type: Collection Failure
Message: 1804 at c:oracleagent10g/sysman/admin/scripts/db/esaDbUtils.pl line 290.
There are also several "Missing Properties : [AdrHome,ConvertFromCharset,needCharsetConvert]" errors listed too.

I've looked into the 1804 error and from what I could find, its a perl-related issue with not being able to get the ORACLE_HOME information.

- I verified that ORACLE_HOME was set in the environment variables and even rebooted to make sure it was being picked up properly. That didn't work.
- I added "$ENV{ORACLE_HOME}='c:\oracle\product\11.2.0\dbhome';" to the esaDbUtils.pl file. That didn't work either.
- I added the GC security certificate to the trusted certificates on the target box in case it was some kind of SSL issue. I don't get the annoying "invalid certificate" warning, but it didn't fix it.