Portal administration page won't load

[cscheffold]

I'm having a very frustrating problem with Cognos BI 8.3

I've installed it on RedHat Enterprise Linux with the standard Apache 2.0 web server and Oracle 11g database.

Everything seems to work fine with the exception of the Administration page in the portal. When I try to launch it, the system just sits there and never goes anywhere. Eventually after a long wait it will return an HTTP 500 error. I can't find anything in the logs.

Does anyone have a suggestion of what I can do to troubleshoot this? Is there a way to turn up the logging on the Cognos server so I can get more information?

I've installed on other servers without any trouble - so this is really puzzling me.

Thanks
Charles