CakePHP Questions

Don't use the IP the address, what about proxy's for example?

Best way is is to use database sessions, a database is made to query on so it's the best candidate. When your user logs on, set the...

When developing it might be handy to enable debugging in only one controller.

Then you can always put:

Configure::write('debug', 2) in that controller. That will show the debug info again.

Same goes...

If it's blank, then most likely a fatal error happened.

Have you turned on debugging?(Configure::write('debug', 2)) and checked your apache logs?

Probably a mistake in the controller Add method.