Configuration changes can be made to the PIX either through the Command Line Interface (CLI) or using a GUI such as Adaptive Security Device Manager (ASDM). However, you should not use both of them simultaneously as it causes very erratic behavior in terms of what gets applied to the PIX configuration by ASDM.
When PIX is accessed via ASDM, it imports the current configuration from the PIX and works from the configuration imported by it when making and applying changes. If a change gets made on the PIX while a CLI and an ASDM session are open, then ASDM no longer works with what it "thinks" is the PIX configuration. As such, you can see very erratic behavior and there can be a difference in the actual changes applied to the PIX configuration versus the expected change that should have been applied to the configuration.
Make configuration changes to the PIX only through one of these methods in order to prevent erratic behavior. If you make changes to the configuration via the CLI, make sure to close out any open ASDM sessions and then reopen ASDM when it is required to work with GUI. Similarly, close out any CLI session to the PIX when you make changes through the ASDM session.